(VAYENAS) INTL. SYMP. ON PHYSICAL CHEMISTRY AND ITS APPLICATIONS FOR SUSTAINABLE DEVELOPMENT

Mixed oxide materials with high lattice oxygen ion lability, typically ionically (O^2-)-conducting materials, can be used as catalyst supports and tunable metal-support interaction carriers, effectively controlling catalytic properties of the metal particles interfaced with them. This occurs via an effective dipolar layer of ionic promoter species formed at the catalyst particle surfaces, which imposes significant alterations on the adsorption properties of the reactants and reaction intermediates with concomitant dramatic effects on surface catalysis phenomena (catalytic performance) as discovered by Vayenas and his co-workers about three decades ago [1, 2]. The dipolar layer and its intensity (promoter species population) can be controlled electrochemically; the so-called Electrochemical Promotion of Catalysis (EPOC) or NEMCA effect [1, 2] can be spontaneously created on traditional-type highly dispersed catalysts via thermally-driven spillover of ionic species from the support on the nanoparticle surfaces [3, 4].
Remarkable achievements on energy and environmentally important catalytic reactions have been accomplished by this concept of promotion.
An additional innovative effect of the spontaneously created effective-double-layer on metal nano-particles, supported by high oxygen ion lability, has been recently discovered [5-6]. This concerns their stabilization against thermal sintering: a topic of great importance in industrial heterogeneous catalytic processes. A novel interpretative model for the action of the effective-double-layer on the two main mechanisms of particles growth, i.e. large particles’ migration and coalescence (PMC) and Ostwald ripening (OR), and thus on their sinter resistance behavior, was developed and discussed in the present paper together with some experimental results.

The concept of the "hydrogen economy" seems to be moving into the world of political and strategic planning as well as into business and enterprise. This is primarily due to the fact that it has been widely recognized and accepted that major improvements in energy efficiency of electric power generation must be achieved in order to reduce emissions of pollutants and, particularly, greenhouse gases such as CO₂ and CH₄. A major underlying principle in the utilization of hydrogen for power production is that of distributed power generation, which arises primarily due to severe difficulties in hydrogen storage and transportation. To overcome these difficulties, the idea of hydrogen production on the spot and on demand has been gaining ground. This implies that an appropriate hydrogen carrier, which could be liquid (methanol, ethanol, LPG, gasoline, etc.) or a gas (natural gas, biogas, etc.) can be used to extract hydrogen from. The process of small scale hydrogen production and power production by fuel cells is the heart of distributed power generation systems.
Results and Discussion
The fuel processor produces a hydrogen - rich stream which is suitable to be fed into the fuel cell. For PEM fuel cells, the most critical requirement is that the CO content in the feed stream is less than 30 ppm. Thus, the process comprises of the reformer, the water-gas shift reactors (low and high temperature) and the CO selective oxidation or selective methanation reactor(s) which minimize CO.
The reformer requires significant amounts of heat to be transported to the reformation zone. For this reason it is designed as a heat exchanger. In one concept, both, the reformation and the combustion catalysts are deposited on opposite sides of plates or tubes, in the form of thin films. This results in a very compact reformer with a high capacity for hydrogen production and high thermal efficiency. The reformation catalyst is normally Ni-based with a carrier designed to enhance its capacity to resist carbon deposition. To this effect, various promoters can also be added. The combustion catalyst is usually Pd-based with provisions to enhance its maintenance in the oxidized form, which is the most active in the fuel combustion process.
Concerning the water-gas shift reaction, it has been found that the catalytic performance of supported noble metal catalysts depends strongly on the nature of the metallic phase and the nature of the metal oxide support employed. Platinum catalysts are generally more active than Ru, Rh and Pd, and exhibit significantly improved activities (by 2 orders of magnitude) when supported on "reducible"(CeO₂, TiO₂, YSZ, MnO, Fe₂O₃, La₂O₃) rather than on "irreducible" (Al₂O₃, MgO, SiO₂) metal oxides. Specific reaction rate (TOF) does not depend on loading or crystallite size of the metallic phase. The activity of Pt/TiO2 catalysts can be further improved with decreasing the primary crystallite size of the support. Based on results of temperature programmed reduction (TPR), and in situ Raman and FTIR spectroscopies, this behaviour has been attributed to the higher reducibility of smaller titania crystallites. The catalytic performance of titania-supported platinum catalysts can be further improved by addition of small amounts of alkali (Na, K, Li, Cs) or alkaline earth (Ca, Ba, Sr, Mg) promoters. For optimized catalysts, specific activity (TOF) is about four times higher, compared to that of unpromoted Pt/TiO₂. Results of H₂^- and CO-TPD experiments demonstrate that promoters affect the population and strength of adsorption sites located at the metal support interface, which are suggested to be catalytically active.
The catalytic performance for the reaction of the selective methanation of CO depends strongly on the nature of the dispersed metallic phase and oxide support employed. Activity for CO/CO₂ hydrogenation is much higher for Ru and Rh catalysts, compared to Pd or Pt, and is significantly improved when supported on TiO₂, compared to Al₂O₃, CeO₂, YSZ or SiO₂. Both hydrogenation reactions are structure sensitive, and specific activity (TOF) increases substantially with increasing Ru crystallite size. Addition of up to 30% water vapour in the feed does not practically affect conversion of CO but retards CO₂ methanation, thereby expanding the temperature window of operation for the title reaction.

Tungstated zirconia supported on multi-walled carbon nanotubes (WO_x-ZrO₂/MWCNT) has been characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), NO_x temperature programmed desorption (NO_x-TPD) and probe reaction of cyclohexanol dehydration in liquid water. TEM and XRD establish that the ZrO₂ grafted to MWCNT are tetragonal crystalline nanoparticles of about 2 nm [1]. XAS and thermal gravimetric analysis indicates that the tungstated zirconia nanoparticles are hydrothermally stable at 200°C and NO_x-TPD [2] was used to measure the interaction of impregnated WO_x with ZrO₂/MWCNT; the WO_x preferentially interacts with the surface of ZrO₂ until about a monolayer (~4 W/nm²) of coverage is reached when a WO₃ particulate phase develops. At a coverage of 8 W/nm², WO₃ can be detected by XRD. The turnover frequencies (TOF) normalized per W atom for cyclohexanol dehydration at 215°C at W surface densities of 2, 4 and 8 W/nm² are 0.043, 0.029 and 0.027, respectively, compared to a commercial bulk WO_x-ZrO₂ with W surface density of 5 W/nm², where it is 0.021. Thus, the TOF of the WO_x-ZrO₂/MWCNT at 2 W/nm² is about twice that of unsupported WO_x-ZrO₂ and exceeds the bulk WO_x-ZrO₂ even when the W density is greater than that of unsupported WO_x-ZrO₂. Dividing the bulk 15.5 wt% WO_x-ZrO₂ TOF (based on acid site density) by the TOF (based on a W atom normalization) indicates that on average it requires 3.3 W atoms per acid site. Because the acid site is a hydronium ion in all cases [3], a better interpretation is that fewer W atoms per acid site are required on the low W density WO_x-ZrO₂/MWCNT. Thus we estimate that about 1.6 W atoms per acid site are required on the 2 W/nm² WO_x-ZrO₂/MWCNT.

The rotating lepton model (RLM) of composite particles [1-3], a combination of Gravity, Special Relativity and Quantum Mechanics, is used to compute analytically the masses of two out of the three neutrino flavors on the basis of the masses of hadrons, without any unknown parameters. The results are in good agreement with the Normal Hierarchy of the neutrino flavor masses, which have not been measured independently yet. The computed masses are then used to derive formulae for the masses of the three bosons and the equilibrium pressures inside hadrons and bosons, which were recently measured via deeply virtual Compton scattering. Comparison with the experimental values shows a semiquantitative agreement (within 1%) and supports the idea that the strong force is a gravitational attraction between relativistic neutrinos.

Water is one of the main products of Fischer-Tropsch (FT) synthesis and its effect on the FT rate has been reported to be positive [1], negative [2], or negligible [1]. The void structure plays an important role on the effect of water on the FT rate [1]. Catalysts with large void structures show positive effects of water on the turnover rate, while catalysts with small void structure show negligible effects. In the case of small void structures, the condense H₂O phase may already exist, while large void structures, require higher water pressure for intrapore condensation [1, 3]. Also, it has been reported that these enhancement rates with increasing water pressure are due to stabilization of kinetically-relevant step through H-transfer [4].
Kinetic and spectroscopic experiments were used to address the influence of the void structure on the effect of water on the rate and selectivity of FT synthesis over Cobalt-based catalysts and the consequences of (i) Cobalt particle size, (ii) extent of reduction of Cobalt, (iii) total pressure of CO/H₂ and (iv) reaction temperature. The consequences of these important parameters on the influence of void structure on the effect water remain unanswered until now. The present study provides a useful and important contribution to the state-of-the-art important kinetic and mechanistic aspects of FT synthesis.
These rate enhancements caused by water are independent of the particle size and the extent of reduction of cobalt. Water plays an important role on the reaction temperature and the total pressure of reactants. Catalysts with large void structures show positive effects of water on the turnover rate at lower reaction temperatures and higher pressures, while at higher reaction temperatures and lower pressures minor effects are observed. Catalysts with small void structure show negligible effects of water on the rate in all experimental conditions. In all cases (small and large void structure), CH₄ selectivity decreases and C₅⁺ selectivity increases with increasing the water partial pressure, except at higher temperatures and lower pressures, where the selectivities are constant. These results reinforce the previous proposal for intrapore condensation of liquid water.

Hydrogen is a very important feedstock in the industry and a promising energy carrier with a main application in internal combustion engines and in fuel cell technology, as a clean and efficient alternative to the massive consumption of fossil fuels. Among the different methods for hydrogen production, catalytic routes are the most interesting ones, for instance via reforming and partial oxidation of hydrocarbons and biomass. In this sense, the addition of electronic promoters chemically (chemical promotion) or electrochemically (electrochemical promotion or EPOC) induces very significant and similar effects on catalytic hydrogen production reactions [1]. Both kinds of promotional phenomena follow the same general mechanism but the usefulness of the latter is highlighted. Hence the EPOC effect is based on the modification of the chemisorption properties of a metal catalyst by the electrochemical migration of promoter ions from a solid electrolyte support (via application of an electric current or potential) [2-3]. Hence, while in chemical promotion, a specific amount of a promoter is added during the preparation step of the catalyst. In the case of the electrochemical promotion, promoter ions are electrochemically pumped between the metal catalyst and the solid electrolyte in a controlled and reversible way during the reaction step [3]. Then, the electrochemical promotion presents several additional advantages, such as the possibility of optimizing the promoter coverage on the catalyst surface at different reaction conditions and the in-situ enhancement of the catalytic activity and selectivity. In this communication, the most important and recent contributions of our group in the electrochemical promotion of different hydrogen production reactions are reviewed. The functional similarities and operational differences between both promotion ways are pointed out, and their impact on the hydrogen production technology is discussed. By this method, the EPOC effects have shown a great interest in H₂ production technology by improving catalytic activity and selectivity under working reaction conditions. In addition, the in-situ catalyst regeneration from carbon deposition, and the possibility of applying the EPOC in the field of H₂ storage, among other novel contributions, lead EPOC to new opportunities in the H₂ technology. For these purposes, novel catalyst films were developed by means of different preparation techniques and also by means of operando surface analysis techniques such as in-situ near-ambient pressure photoemission (NAPP) spectroscopy have been used in order to investigate the origin and mechanism of this phenomenon.

Electrochemical Promotion of Catalysis (EPOC) or non-Faradaic electrochemical modification of catalytic activity (NEMCA) is a promising concept for boosting catalytic processes and advancing the frontiers of catalysis. This innovative field, discovered by the group of Professor C.G. Vayenas in the early 80s [1], aims to modify operando both the activity and the selectivity of catalysts, in a reversible and controlled manner. More than 80 different catalytic systems (total and partial oxidations, hydrogenations, dehydrogenations, isomerisations, and decompositions) have been electrochemically promoted on metal or metal oxide catalysts supported on different ionic conductors [2,3]. These include reaction systems of critical importance in diverse fields of chemical synthesis including the production of commodity and fine chemicals and in the abatement of automotive emissions. EPOC utilises solid electrolyte materials (ionically conducting ceramics) as catalytic carriers. Ions contained in these electrolytes are electrochemically supplied to the catalyst surface and act as promoting agents to modify the electronic properties of the catalyst in order to achieve optimal catalytic performance. Different types of ions such as O^2-, Na⁺, H⁺, K⁺ have been successively used in the literature to boost catalytic properties of catalytic materials. It thus provides a unique means of varying promoter levels at the metal surface under reaction conditions by simply changing the potential of the catalyst film. Therefore, EPOC can be considered as an electrically controlled catalyst-support interaction in which promoting ionic agents are accurately supplied onto the catalytic surface by electrical potential control.
The main technological issue of EPOC is related with the use of continuous metallic coatings interfaced onto dense solid electrolyte supports. On that account, the metallic dispersion of the catalyst-electrodes, and therefore their catalytic activity, is usually far lower than that of commercial dispersed catalysts. In addition, the thermal stability of continuous metallic coatings is rather low to the sintering phenomenon, especially when using transition metals. This explains why most of the EPOC studies reported in the literature have been performed on Platinum Group Metals (Pt, Pd, Rh) and to a lesser extent on Ag, Ru and Ir. The utilization of pure precious metals catalytic layers is not economically reliable. Furthermore, the thermal stability of pure transition metals coatings deposited on dense solid electrolyte supports is too low to be realistically implemented for catalytic processes. Therefore, some research efforts are focused to achieve EPOC over catalytic dispersed nanoparticles. This plenary lecture will give an overview of recent advances in the quest of electro-promoted nanoparticles including innovative architectures of catalyst-electrodes.

Electrochemical promotion of catalysis (EP or EPOC) or non-faradaic electrochemical modification of catalytic activity (NEMCA) corresponds to the induced reversible modification of the catalytic behavior of metal or metal oxide catalyst-electrodes deposited on solid electrolytes or mixed ionic-electronic conductors (MIEC), resulting from polarization of the electrode/electrolyte interface [1-3]. This electrochemically induced catalytic effect has been attributed to electrochemical pumping of mobile promoter ionic species (e.g. O^2-, H⁺, Na⁺, depending on the solid electrolyte or MIEC) to or from the gas exposed electrode surface under reaction conditions. This results in modification of the electronic properties of the electrode and, concomitantly, to the alteration of its catalytic properties [1-3].
Electrochemical promotion has been demonstrated for a very large number of combinations of solid electrolytes or MIEC, electrodes and catalytic reactions [1-7]. It is an effect of fundamental importance, bridging electrochemistry and heterogeneous catalysis [3], whereas, as it allows for in situ reversible tuning of catalyst performance, it opens up new possibilities for practical application in the fields of heterogeneous catalysis and applied electrochemistry [3-7].
This work highlights key landmarks in electrochemical promotion over the past three decades, with emphasis on the origin and mechanistic understanding of this effect, on the rules of electrochemical promotion and on its functional equivalence to metal support interactions. Moreover, current activities and trends in electrochemical promotion, as well as obstacles to overcome for commercial applications, are also discussed.

During the last two decades, the Electrochemical Promotion of Catalysis (EPOC) phenomenon has been studied extensively for many catalytic reactions, including hydrocarbon oxidation reactions and hydrogenations [1-3]. The EPOC effect is based on the modification of the work function of a metal, which also serves as a working electrode, leading to an alteration in the chemisorption bond strength of the reactants. This effect is observed when small currents or potentials are applied to a catalyst deposited on a solid electrolyte. In the majority of the studies, the catalysts/electrodes consisted of porous noble metal films (Pt, Pd, Rh) prepared, for instance, by calcination of organometallic pastes [4]. This results in low metal dispersion and low active surface area, therefore limiting the overall catalytic activity. In view of further practical application of the EPOC phenomenon to industrial catalysts, we should be able to enhance the activity of nanodispersed materials. In this study, for the very first time, we observed an enhanced catalytic activity of a Pd nanodispersed catalyst supported on a porous Co₃O₄ semiconductor film. The Pd/Co₃O₄ composite powder was deposited on an yttria-stabilized zirconia (YSZ) solid electrolyte without the presence of an interlayer film. The observed enhancement was non-Faradaic, with apparent Faradaic efficiency values as high as 80. The Pd/Co₃O₄ catalyst was characterized thoroughly by means of a wide variety of physicochemical techniques, such as TEM, SEM, TGA, ICP and BET. Using supported catalysts as catalytic films for electrochemical promotion studies may lead to the practical utilization of EPOC in the chemical industry or in gas exhaust treatment.

Triode operation of fuel cells is an alternative approach for enhancing fuel cells’ power output under severe poisoning conditions which lead to high overpotentials. This innovation was developed and applied firstly on SOFCs and later on PEMFCs [1-4]. In a triode fuel cell, in addition to the anode and the cathode, there is a third auxiliary electrode in contact with the solid electrolyte (e.g. polymer electrolyte membrane in the case of PEMFCs). This electrode forms, together with the cathode, a second (auxiliary) electric circuit operating in parallel with the conventional main circuit of the fuel cell. The auxiliary circuit runs in the electrolytic mode, pumping ions (i.e. protons in the case of a PEMFC) from the cathode to the auxiliary electrode. This way, imposition of a potential difference between the auxiliary electrode and the cathode permits the primary circuit of the fuel cell to operate under previously inaccessible, i.e larger than 1.23 V, anode - cathode potentials.
The triode operation of humidified PEM fuel cells has been investigated both with pure H₂ and with CO poisoned H₂ feed over commercial Vulcan supported Pt(30%)-Ru(15%) anodes. It was found that triode operation, which involves the use of a third, auxiliary, electrode, leads to up to 400% power output increase with the same CO poisoned H₂ gas feed. At low current densities, the power increase is accompanied by an increase in overall thermodynamic efficiency. A mathematical model, based on Kirchhoff’s laws, has been developed which is in reasonably good agreement with the experimental results. In order to gain some additional insight into the mechanism of triode operation, the model has been also extended to describe the potential distribution inside the Nafion membrane via the numerical solution of the Nernst-Planck equation. Both models and experiments have shown the critical role of minimizing the auxiliary-anode or auxiliary-cathode resistance, and this has led to improved comb-shaped anode or cathode electrode geometries.

The production of synthetic fuels from renewable energy could be a more efficient solution for a sustainable future without the need of huge investments for modifications in the existing infrastructure [1,2]. The raw material of synthetic fuels via the Fischer-Tropsch process is syngas (H²⁺CO) and is primarily generated by fossil fuels. The co-electrolysis of carbon dioxide and steam in a solid oxide electrolysis cells (SOECs) is an emerging route to produce syngas and thus store renewable electricity in the form of chemical bonds [2].
The commonly employed materials for fuel electrodes (cathode) in the process are Ni based cermets that exhibit high ionic-electronic conductivity and electrocatalytic activity. Nevertheless, Ni-YSZ electrodes suffer from coarsening under redox conditions and coking under carbon rich environments [3]. To circumvent coarsening, a reducing agent, such as hydrogen or carbon monoxide, is always co-fed with CO₂-H₂O in order to keep Ni in a reducing state [2].
Perovskite oxide ceramics (ABO3) are the most promising alternative fuel electrodes. Perovskites exhibit mixed ionic-electronic conductivity as single phases and can accommodate several kinds of defects under redox conditions, allowing them to adapt to various external conditions and therefore maintain stability and functionality under redox environments [4]. Lanthanum titanates constitute an intriguing class of perovskites, exhibiting chemical, dimensional, thermal and mechanical stability. By controlling deficiency of the A-site, transition metal nanoparticles may be exsolved to the surface from the perovskite oxide backbone under reducing environments. The grown particles are uniformly dispersed as well as anchored to the perovskite scaffold, thus rendering them more catalytically active and chemically stable compared to the oxide supported counterparts prepared by infiltration [5-7].
Along these lines, here we report on the electrochemical performance of (LaCa)(MTi)O₃ (M=transition metal) as fuel electrodes for high temperature CO₂-H₂O co-electrolysis. The cells are characterized and tested at 800-850°C under several feed mixtures (CO₂/H₂O, H₂O/H₂, CO₂/ H₂O/H₂, CH₄/H₂O-CO₂) and applied voltages.

Vayenas et al have proposed an unexpectedly simple but extremely powerful method for elementary particle physics. It is based upon a straightforward synthesis of quantum mechanics and special relativity. The central idea is to replace Newton’s classical gravitational law with the expression (where is the rest mass of neutrino and the Lorentz factor) for the rotating neutrino model (RNM) which was invented to describe the strong force in the nucleus. Here, an attempt is made to revisit ideas used in continuous media for dealing with singularities, in order to modify in a different way the classical gravitational potential. The resulting modified gravitational potential is used for the RNM configuration, Vayenas results are recovered.

Graphene is a perfect 2D crystal of covalently bonded carbon atoms and forms the basis of all graphitic structures with superior properties [1] that can be exploited in many research areas. Nevertheless, these structures cannot have significant impact until efficient production techniques develop to harvest their unique properties in global applications and devices. Chemical Vapor Deposition (CVD) is the most well-known method of graphene growth [2]. The fabrication process is rather complex, as it involves multiple steps such as hydrocarbon decomposition, carbon adsorption and subsequently, diffusion on the catalytic substrate, the generation of the nucleation point and finally, the growth. As the nucleation happens at random places on the surface, this method by default results in micro-meter sized multi-domain layers. Moreover, the separation and transport steps add further defects and contaminations, which further impair the ideal physical properties of these materials. In contrast to a solid catalytic substrate, graphene growing on Liquid Metal Catalysts (LMCat) might be a solution for the production of defect-free single graphene domains at high synthesis speeds due to the enhanced atomic mobility, homogeneity, and fluidity of a LMCat.
In-situ monitoring of such a complex procedure is of paramount importance for the control of graphene growth and the understanding of growing kinetics. Among other optical techniques, Raman spectroscopy has been used extensively for studying nanomaterials in general and graphene in particular. Performing in situ Raman spectroscopy at high temperatures, however, needs special considerations, otherwise the weak Raman signal could be easily dominated by the intense thermal radiation. In our case, a UV laser line at 405 nm was used to reduce the black body radiation effect. Raman spectra were acquired on liquid Cu during growth and it verified the existence of graphene even at its primary stages. This result is of paramount importance since it is the first time that a chemically sensitive technique like Raman spectroscopy was implemented for the in-situ monitoring of graphene growth. Beside Raman spectroscopy, a novel metrology system based on reflectance spectroscopy for the in-situ monitoring of surface changes during graphene growth by taking advantage of reflectance variations was developed. Simultaneously, reflectance fluctuations on the surface of copper are monitored and analyzed. The results indicated that the growth rate of graphene can be estimated from the measured differential reflectance.
We will present processing strategies for the production of macro-scale CVD-graphene/polymer nanolaminates based on the combination of ultra-thin casting, wet transfer and floating deposition [3, 4]. These composites possess excellent mechanical and electrical properties and can be employed as coatings for EMI shielding or electro-active displays in a variety of applications. This can assist in the protection of membranes, art objects and particularly paintings. Finally, the use of large transparent graphene veils for the protection of art works will also be covered in this presentation.

The wealth of particles generated in high energy collisions are explained by the standard model. In this model there are sixteen particles which are considered elementary. To that one has to add a seventeen one, the Higgs particle. The force acting between elementary particles is the strong force mediated by gluons, the weak force mediated by the bosons W⁺, W^- and Z⁰ and the electromagnetic interaction, mediated by photons. The gravitational force, though present, is so weak that it is neglected.
About a decade ago Prof. Vayenas [1,2] suggested that the strong force is generated by rapidly moving particles with a velocity, v, very close to that of light, c. This results in a significant increase in the Lorentz factor (1-vv/cc)^-1/2 hence also in the effective mass of the moving particles. The Lorentz factor was introduced into the gravitational force expression. An existing experimental report showed that the proton contains three components and it originally led to the three-quark model of the proton and neutron. Prof. Vayenas suggested, that the proton and neutron are composed of three particles rotating at a high speed very close to c and are interacting through the gravitational force. Solving for the bound states of the rotating particles, in analogy to the Bohr model, led to a LOrentz factor ~10¹⁰ and a rest mass of 0.0437 eV/c² for the rotating particles which, at the time, was of the order of the upper limit for the neutrino and is now known experimentally to be very close to the measured mass of the neutrino. Thus, in this model the strong force does not require the existence of gluons and the quarks are presented as moving neutrinos. The mass of the particles composed of three rotating neutrinos is of the order of 1 GeV/c² or more. An outstanding success of the new theory is a calculation of the pressure inside a proton. in full agreement with an experimental value recently reported.[3]
In recent years Prof. Vayenas extended this analysis to other particles generated in high energy collisions. Thus in the new model the list of elementary particles reduces to only electrons and positrons and neutrinos. All the rest are either superfluous (the gluons), are replaced by neutrinos (quarks) or are a combination of neutrinos and electrons. This drastically simplifies the model of matter and our understanding of the universe along the line of thinking of Albert Einstein that was looking for a unification of the forces in nature.

Solid state proton conductors can operate at high temperatures (> 500 ^oC) and have been applied in the construction of sensors, fuel cells and hydrogen separators. In the past two decades, they have also been used in the construction of electrochemical membrane reactors. The advantage of high temperature conductors, versus those operating at low temperatures, is that they operate in the temperature range within which a large number of industrially important catalytic hydro-reactions and dehydrogenation reactions take place. In most of the earlier applications of electrochemical membrane reactors in catalytic research, the reaction of interest took place on the working electrode while the counter electrode served for the formation of protons from a hydrogen containing compound.
These electrochemical reactors, however, would become more competitive if useful chemicals were produced on both, working and counter electrodes [1, 2]. Results on two reaction systems in which both, cathode and anode were properly utilized are presented here. The first is the production of methanol and oxygen from CO₂ and H₂O. Steam and CO₂ are introduced at the anode and cathode side, respectively, of a co-ionic (H⁺ and O^2-) conductor. Steam is electrolyzed to form O₂ and protons (H⁺). The latter are transferred to the cathode and react with CO₂ to form CH₃OH. The second system is an electrochemical Haber-Bosch (H-B) Process [3]. A mixture of steam and methane is fed to the anode chamber. Nitrogen is fed over the cathodic electrode. Hydrogen produced at the anode is "pumped" electrochemically (in the form of protons) to the cathode, where it reacts with N₂ to produce NH₃. A preliminary energy analysis indicates that, at faradaic efficiencies above 30% and at cell bias as low as 0.4 V, the electrochemical H-B becomes more efficient than the conventional H-B Process with respect to both, energy consumption and CO₂ emissions.

During the last decades, several natural gas (NG) reservoirs were found to be rich in CO₂ (> 40 vol%), and this led to an intense effort for the development of a dry reforming of methane (DRM) catalytic technology (CH₄ + CO₂ to 2 CO + 2 H₂) with a favorable H₂/CO gas ratio for liquid fuels (Gas To Liquid, GTL) and other useful chemicals (e.g., DME, MeOH, acetic acid) by the catalysis research community and related industries [1]. Biogas (a renewable energy source) can also be a suitable feedstock for the DRM catalytic technology [2].
Practical problems related to the irreversible coking phenomena, especially on the less-costly attractive Ni-based catalysts, remain one of the main obstacles for the catalytic DRM technology to find industrial applications. It is well known that an in-depth understanding of the elementary steps related to carbon deposition and removal chemistry on Ni or other relevant metal supported catalytic systems along with their micro-kinetic analysis is a key factor for the future development of highly active and
carbon - resistant DRM catalytic systems, preferably at temperatures lower than 750 ^oC.
This keynote lecture will present the use of various transient and isotopic experiments (use of ¹⁸O₂, ¹³CO₂ and ¹³CH₄) to elucidate the role of metal cation dopant in Ce_1-xM_xO₂ (M = Ti⁴⁺, Pr³⁺) used as support of Ni, and the use of Pt in the NiPt alloy supported on Ce_0.8Pr_0.2O₂, in reducing the carbon accumulation to a remarkable extent during DRM at 750^oC. In particular, the importance of carbon gasification by labile oxygen of support to the formation of CO(g), the contribution of oxygen vacant sites of support to the CO₂ dissociation rate and re-oxidation of support, and the quantification of the origin of carbon accumulation (CH₄ vs CO₂ activation route) will be elucidated [3, 4]. Other experimental approaches reported in the literature for the understanding of carbon deposition and removal chemistry on supported Ni and other metals will be presented. Experimental results from the SSITKA technique (use of ¹³CO₂ or ¹³CH₄) will be presented to demonstrate the effect of metal dopant on support and Pt on the active carbon that is strictly associated with the rate of reaction.

Global warming triggered by growing of the greenhouse gases concentration in the atmosphere actually represents the biggest world ecology problem. Carbon dioxide is one of the most important greenhouse gases because it is the main reason for global warming [1] Therefore, effective solutions to the global warming problem should be connected with the lowering of the carbon dioxide concentration in the atmosphere. One of the feasible protocols is to employ carbon dioxide as starting material and to convert it to the valuable compounds in various industrial processes which are very important. [2] For this purpose, iron-based materials act as a one of the most effective catalytic materials for carbon dioxide hydrogenation to methane, methanol and other simple important hydrocarbons. [3] Heterogeneous catalysis is connected with the active surface of catalysts. Therefore, the subject of the presented study is to investigate the influence of the catalyst’s physical state on its activity in hydrogenation of CO₂.
Four types of iron oxide catalysts were prepared by high temperature decomposition of Iron (II) oxalate in the air. Afterword, its catalytic performance was studied at low pressure (1 bar) and low temperature (325°C) in the microreactor, Microactivity Effi, connected with a gas chromatograph for the detection of the reaction products. Depending on the order and rate of reaction, components mixing four different samples of the nanostructured iron oxide catalyst were prepared. After high temperature decomposition the composition of the prepared catalyst was determined by XRD and only hematite and magnetite in a various ratio between 90:10 down to 40:60 (hematite: magnetite) was observed in the emerging catalysts. Bigger differences between these catalysts were observed during reduction of the iron oxide in the hydrogen atmosphere by the XRD technique. Part of the samples produced zero valent iron but the second parts of the samples were reduced only to the form of pure magnetite. Also, observed catalytic activity of the prepared catalysts was different. The highest reaction rate, but also the lowest stability, was observed for catalysts which were reduced in the hydrogen atmosphere to zero valent irons, whereas catalysts which were reduced only to magnetite were substantially stable in selectivity of the production of methane in comparison with carbon monooxide. Unfortunately, total reaction rate was, in this case, slower. On the other hand, microstructured commercial Iron(II) oxide used as reference did not produce hydrocarbons (mainly methane), only carbon monoxide was observed as a carbon based product with this catalyst.

Microcomputed Tomography has become a powerful and widely used tool for non-destructive testing and can be used for mapping the complex 3D structures of cracks and their interactions. The materials of most oil and gas transport pipes, buried or submerged, such as high strength low alloy steels, for example, are likely to suffer corrosion, degradation and fracture due to the corrosive environment. Similarly, cracks are one of the most severe types of discontinuities in a welded joint because they are strong stress concentrators. High tensile stresses develop in the weld region as a result of the localized thermal expansion and contraction associated with the welding thermal cycle. To better characterize the cracking behavior, it is important to gain information about the evolution of the 3D crack network. The search for improving image quality in the inspection of steel samples using X-ray beams, however, is still challenging because of spreading effects that can cause noise in the 3D image. For this purpose, we performed microCT tests to verify cracks due to corrosion, loss of weld adhesion, and cracks applying to mathematical filters to improve the final image quality. To enhance details of the greyscale micro-CT image, the image was filtered using anisotropic diffusion (AD) and unsharp mask (UM) filters [1], which have been found to be highly effective for enhancement of digital fractured media [2,3]. AD is an edge-preserving noise reduction filter that has been shown to enhance the signal-to-noise ratio of tomographic images in a variety of contexts while preserving edges [4]. UM is highly effective at sharpening edges without excessively strengthening the noise [1]. It was possible to verify cracks around 0.66 mm for corrosion cracks and 2.67 mm for cracks due to loss of weld adhesion. Also, observation of the continuities of the cracks in the 3D visualization of the inspected materials was possible.

The term "induced codeposition" was already coined by Brenner in 1963 to describe a process where certain elements such as tungsten (W),that cannot be deposited alone from their aqueous solutions, are readily codeposited with iron-group metals. Indeed, alloys of W with iron-group metals can readily be formed using, for example, a solution of NiSO₄ and Na₂WO₄, with citric acid added as a complexing agent. In this particular case, it was shown that the NiW alloy is deposited from an adsorbed complex containing both metals, while Ni is also deposited in parallel reactions from its complex with citrate. The term induced codeposition may also be used to describe a process where a metal, that can barely be deposited alone, with a low current efficiency (FE) and poor adherence of the deposit, is readily deposited in the presence of other metal ions. This is the case of rhenium (Re), which can be electroplated alone at FE a ≤ 7% and poor coating quality. By adding a suitable iron-group metal salt to the bath, we have obtained coatings with a Re content as high as 93 at.% and a FE as high as 96%.
In this plenary presentation, we review our study of the electrodeposition and electroless plating of Re-based alloys. Issues such as the catalytic effect of iron-group metals on the deposition of Re, the early stages of deposition, the effects of bath additives and pulse plating, electroless plating, and the associated microstructures are discussed. We also discuss the effect of other alloying elements (e.g. Sn or Ir) on the resulting deposition process and microstructure. Similarities and differences compared to induced codeposition of W are discussed. The fundamental aspects are complemented by some applied aspects, e.g. with respect to thermal barrier coatings and catalysis.

In this lecture we will focus on low-energy, non-relativistic quantum-mechanical three- and four-charge-particle systems which are of a significant interest in different fields of atomic, muonic and molecular physics. Some of the particles in the few-body systems may have additional nuclear strong interactions between them. An appropriate inclusion of these forces in calculations and estimation of their influence on the properties of the few-body systems is an important but challenging task.
We will present different Coulomb three-body systems, which are related to the problems of the muon-Catalyzed-Fusion cycle (muCF-cycle). Secondly, certain few-body systems and problems in the field of the low-energy antiproton physics and anti-hydrogen formation and annihilation reactions will also be considered and discussed [1].
Additionally, we will present various theoretical methods and few-body techniques, which are based on the three-body Faddeev [2] and/or modified Faddeev-type equations [1]. Special attention will be given to comparison between theoretical results and available experimental data. Other theoretical numerical methods such as variational, adiabatic, and hyper-spherical will be briefly introduced and discussed as well.

Soft microstructured materials is the class of materials where computer simulations have enjoyed the most rapid advances in the last two decades due to the development of several innovative molecular simulation techniques (such as multiple-time step Molecular Dynamics, chain connectivity altering Monte Carlo, and coarse-grained schemes), the introduction of advanced, very accurate force fields and the use of graphics processing units (GPUs) which has revolutionized the field.
In our presentation, we will highlight all these extraordinary developments, we will stress the importance specifically of atomistic simulations in substantially improving our understanding of the structure-property-processing relationship in materials with a highly complex internal microstructure [1], and we will show how molecular modelling can be used as a true design tool for new multifunctional materials by unravelling the fundamental physicochemical properties governing the performance of the final product in actual applications [2].
In particular, we will demonstrate how we can get help from nonequilibrium thermodynamics [3, 4] to design novel methodologies that can lead to the efficient computation of the viscoelastic properties of complex fluids or to the formulation of more accurate constitutive models describing their flow behavior as a function of their internal microstructure [5, 6].

Inspection of the decay product Tables of Hadrons, Mesons and Bosons [1,2] shows that all these composite particles decay eventually to neutrinos, antineutrinos, electrons and positrons. Conversely, these leptons can be used to synthesize all known composite particles by forming, via gravitational confinement, rotating rings of super relativistic neutrinos in the cases of Hadrons and Mesons [2,3] and mixed superrelativistic electron/positron – neutrino rings in the case of bosons [4-7]. As shown recently, [2-7] the masses of these composite particles, i.e. hadrons, mesons and bosons, can be computed within typically 1% from first principles by constructing Bohr-type rotating lepton models using special relativity and gravity as the centripetal force and achieving quantization via the de Broglie wavelength equations [2-7]. These models do not contain adjustable parameters. Recent work has shown that the use of General Relativity (GR) instead of Special Relativity (SR) leads to the same conclusions [8,9]. Also, [10] it was recently shown that the formation of these rotational structures is very strongly catalyzed by positrons or electrons which, via their much larger rest mass than that of neutrinos, accelerate neutrinos to strongly relativistic velocities, thus dramatically increasing their relativistic and gravitational mass and facilitating the formation of the neutrino rotational rings. Bosons forced via electron-neutrino pairs also facilitate hadronization [5,6,7,10]. The main hadronization reaction, i.e. proton formation from three neutrinos and a positron, 3ν_e+e⁺ → p, is extremely exothermic (some 20 times more exothermic than H fusion) and may thus have played a significant role in the Big Bang. It could also, in principle, play a role for future terrestrial power production under controlled conditions. In conclusion, it appears that quarks are polarized relativistic neutrinos, that the Strong Force is relativistic gravity between neutrinos, and that the Weak Force is relativistic gravity between electrons/positrons and neutrinos. It also appears that electrons and positrons have played a key role in the formation of our Universe as we know it today by catalyzing the strongly exothermic hadronization reactions leading to the formation of protons, neutrons and, eventually, atoms.

Pt supported on carbon electrocatalysts are the most efficient and stable materials for both the oxygen reduction reaction (ORR) at the cathode and the hydrogen oxidation reaction (HOR) at the anode of polymer electrolyte membrane fuel cells (PEMFCs) (1). In this respect, there is increasing demand to reduce cost and therefore, the amounts of Pt used. This can be achieved by increased catalyst activity and/or utilization (2). To reach this goal, there are two approaches: (a) enhancing the specific activity or (b) increasing the specific surface area of the catalyst by forming a fine dispersion. The performance and stability of the (electro) catalysts strongly depends on the physicochemical characteristics, such as the surface area, the crystalline structure, the size and shape of the particles, and the interactions with the support. Both approaches for Pt reduction can be followed separately or combined by exploiting the differentiations induced to the metal by the surface chemistry of the support to result in customized properties and control its performance. When the dispersion of the metal is high, its metal atom is accessible to reactants and available for catalysis, maximizing the efficiency of the metal and minimizing the cost. Reducing the size of the metal in atoms or small groups of atoms can significantly increase both the active surface and the activity of the catalyst through diversification or strengthening of the metal-support interactions3.
In this work, we have developed Pt/f-MWCNTs (f-MWCNTs=covalently functionalized MWCNTs) based electrocatalysts with different surface functionalities and Pt loadings. The deposition of the metal was achieved by using the polyol synthetic procedure: reduction of metal precursor salts in an ethylene glycol solution. Through a structural and chemical characterization study of the materials, the introduction of certain groups on the sidewalls of the carbon support resulted in differentiation of the properties, not only in terms of quantitative deposition and dispersion, but also with respect to metal-support interactions, platinum crystal properties and/or oxidative states. The present work addresses scientific issues regarding the most challenging core component of a PEM fuel cell: the Pt based electrocatalyst. This work proposes a comprehensive effort to explore a new approach and exploit the differentiations induced on the metal by the surface chemistry of the support. The introduction of pyridines on the sidewalls of the carbon support can differentiate the metal deposition, not only in terms of dispersion and the obtained morphology, but also with respect to metal-support interactions on platinum properties and its oxidative state. The aim is the interpretation of the catalyst’s electrochemical behavior through a structural and physicochemical characterization study. It is shown that the substrate can play a decisive role on the size and functionality of the electrochemical interface. This approach constitutes a promising route for developing materials with innovative features aiming to a serious reduction in the Pt loads, thus resulting into increased catalyst activity and metal utilization.

Na-ion batteries are the most promising energy sources for stationary applications. Numerous electrode materials that are used in Li-ion cells seem promising for use in Na-ion cells as well. A stable long term capacity, however, is yet to be achieved by these electrode materials. The present talk will compare the differences between the sodiation and lithiation mechanisms of TiS₂ which can serve as a cathode material. X-ray diffraction and electron microscopy illustrate that cycling with respect to lithium results in long term electrochemical stability, whereas with respect to sodium, irreversible phases and cracks form, giving rise to a capacity decay. The experimental results are supported with continuum mechanics studies on stress evolution during cycling.

A novel method is discussed for determining series of elementary steps in the reduction process of oxygen on an oxide.[1,2] The method is based on exposure of the oxide, first to ¹⁶O₂, and then to ¹⁸O₂ while monitoring the rate at which ¹⁶O¹⁸O molecules are generated and evaporate into the gas stream, under short time conditions. The parameters to be changed are oxygen partial pressure, P(O₂) (being the same for both isotopes) and acceptor doping level [A] of the oxide. ¹⁸O₂ can be applied in the form of a pulse or a step function. The rate of ¹⁶O¹⁸O generation is shown to depend on P(O₂)^m1 [A] ^m2. Another parameter that can be determined is J₀, the rate of the forward reaction in the slow step of the series which depends on P(O₂)^m3 [A] ^m4. The indices {m₁,m₂, m₃, m₄} are, in most cases, typical for a particular series of elementary steps. The series to be identified consist of fast steps ending with a relative slow one. This method is then different from the one based on the time dependence of the concentrations of ¹⁶O₂, ¹⁶O¹⁸O and ¹⁸O₂ in the gas phase.[3,4] The method is quite sensitive and even changing the source for electrons from the valence band to the conduction band changes the value of the exponents {m1,…,m4}.
The analysis assumes that the dependence of the concentrations of point defects (oxygen vacancies and electrons) in the outer most layer of the oxide on P(O₂) and [A], is known. The method was applied so far under the conditions that the P(O₂) and [A] dependence is the same as in the deep, neutral bulk. This is shown to be indeed the case under many prevailing conditions.[5] Other P(O₂) and [A] dependence of the concentrations of point defects in the outer most layer of the oxide bulk are also presented.[5] Thus it is possible to determine series of elementary steps on all type of oxides which are undoped or acceptor doped.
The method is not limited to oxygen isotope exchange and can readily be extended to other isotopes e.g. ³⁵Cl₂ and ³⁷Cl₂ exchange. Exchange of H₂ and D₂ requires special attention due to the mass effect on the chemistry of hydrogen and we show how to cope with it.[2]

Understanding the origin of quark confinement in hadrons remains one of the most challenging problems in modern physics. Recently, the pressure distribution inside the proton was measured via deeply virtual Compton scattering. Surprisingly, strong repulsive pressure up to 10³⁵ pascals, the highest so far measured in our universe, was obtained near the center of the proton up to 0.6 fm, combined with strong binding energy at larger distances. We show here that this profile can be derived semi-quantitatively without any adjustable parameters using the rotating lepton model of composite particles (RLM), i.e. a proton structure comprising a ring of three gravitationally attracting rotating ultrarelativistic quarks. The RLM synthesizes Newton's gravitational law, Einstein's special relativity, and de Broglie's wavelength expression, thereby conforming to quantum mechanics. This also yields a simple analytical formula for the proton radius and for the maximum measured pressure which are in excellent agreement with the experimental values.

The fundamental physical description of Nature is based on two mutually incompatible theories: Quantum Mechanics and General Relativity. Their union in a theory of Quantum Gravity remains one of the main challenges of theoretical physics. A common feature of candidate theories of Quantum Gravity is the existence of a minimal observable length of the order of the Planck length [1]. This prediction, though, is in contradiction with Heisenberg's Uncertainty Principle. In fact, according to this principle, it is possible to observe any length while increasing the uncertainty in momentum. In the context of Quantum Gravity Phenomenology, that studies quantum-gravitational effects in low-energy systems, Heisenberg's principle is then modified into the Generalized Uncertainty Principle (GUP) [2]. The GUP then imposes a minimal uncertainty in position and predicts a deformed commutation relation between position and momentum [3]. In this talk, after introducing the basics of the Uncertainty Principle, I will show how the GUP can change known aspects of standard Quantum Mechanics, leading to ways to test theories of Quantum Gravity.

Electrocatalysis plays a pivotal role in electrochemical energy conversion devices such as fuel and electrolysis cells by decreasing the overpotential of electrode reactions. Understanding mechanisms of the electrode reactions and the nature of active sites and intermediates is an important clue in designing efficient and durable electrode materials for practical applications. Various approaches can be utilized in order to obtain information regarding the mechanisms of electrocatalytic reactions and the nature of the active sites; among them are electrochemical methods, operando spectroscopies, ab initio calculations and kinetic modeling.
In this presentation, we will illustrate these approaches by considering reactions of outstanding practical importance [1-6] such as the oxygen reduction (ORR) and the oxygen evolution reaction (OER), the hydrogen evolution (HER) and the hydrogen oxidation reaction (HOR).

Novel catalyst designs aiming at the development of energy-efficient, low-cost and sustainable processes are of great interest for applications to fuel and chemical production, and to environmental pollution abatement. Identification of the active catalytic site and design of catalysts with 100% atom efficiency has been a long-standing goal in heterogeneous catalysis. A promising approach to reaching this goal through the controlled preparation of isolated single-atom heterogeneous catalysts has emerged in recent literature. For catalytic metals, atomic dispersion affords better utilization, different (often better) selectivity than the extended metal, as well as new prospects for low-cost and green process development. Isolated supported metal atoms may be viewed as species bonded to a support, the latter serving as a ligand. An analogy between a homogeneous and a heterogeneous single-site catalytic center can thus be made. Single atom sites catalyze some, but not all reactions. It is crucial to understand the mechanisms behind catalysis by supported single metal atoms, as this will guide new, improved catalyst designs. In this presentation, suitably stabilized catalytic sites as single metal atoms/cations on various supports will be showcased by drawing examples from a variety of reactions: the low-temperature water-gas shift reactions, methanol and ethanol dehydrogenation and steam reforming reactions, the direct methane conversion to oxygenates, and selective hydrogenation reactions on single-atom alloys. Reaction mechanisms involving single metal atoms/cations often transcend support structure and composition, thus allowing flexibility in the choice of the support. A unique "signature" of the metal (Au, Pt, Pd, Ni, etc.) at the atomic state is preserved, distinct however from the corresponding extended metal catalyst.
A new class of single-atom heterogeneous catalysts will be presented, namely single-atom alloys that comprise of catalytically active elements like Pt, Pd and Ni alloyed in a more inert host metal like Cu, Au or Ag at the single-atom limit. Single-atom alloys offer a unique approach towards rational catalyst design, one that combines surface science, catalysis and theory in a most efficient way. Model surfaces and nanoparticles that can host isolated atoms in the surface layers behave similarly in escaping the linear scaling relationships and allow for the rational fine-tuning of activity and selectivity. Good stability is imparted by the strong metal-metal bonds between the host, the minority metal, and atomic dispersion. This can be maintained at high temperatures. Resistance to CO poisoning and coking are additional advantages of these promising materials, as will be shown in the presentation where examples will be drawn from alkyne and alkadiene hydrogenation, and alkane dehydrogenation. Novel synthesis methods and the stability of single-atom metal catalysts in various supports and reaction environments will be discussed.

Molecular sized pores are not only critical for ion exchange and sorption, but they also provide a unique chemical and steric environment for catalysis. Regular dimensions allow stability of ground and transition states of reacting molecules better than that of larger pore oxide and organic porous materials. This enhances interaction strength and lowers the standard free energies of transition states in a highly selective manner. These properties are analog to qualities that are critical for the high activity of enzymes, for the local constraints and for the local chemical environment at active sites.
Many reactions in petroleum chemistry, such as cracking or isomerization, occur under conditions where the concentration of reacting molecules is low and excellent models to understand reactive interactions under such conditions have been developed. The search for more efficient reactions at lower temperatures, such as eliminations, carbon-carbon bond formation, and the presence of the liquid phase induce complex ordering of reactants, intermediates and products, enabling a subtle way to direct sorption and catalysis. The ordering in protic solvents, such as water, especially leads to new chemistry as acid zeolites transform into a polar oxide environment with hydrated hydronium ions as the stable active site.
The lecture will address the chemical consequences of such an environment and compare it with the environment created in molecular organic frameworks. We will show how water and protic solvent molecules self-organize in this environment and how they impact the thermodynamic state of the sorbed and reacting molecules. It will be shown that the interactions can be designed and controlled via direct synthesis (changing pore sizes and concentration of sites), as well as via the addition of cations, oxidic clusters or organic fragments. Such interactions will be compared to interactions reacting molecules have with coordination compounds and enzyme sites. As examples for catalytic transformations, the lecture will compare elimination reactions of alcohols, alkylation of aromatic molecules and oligomerization of olefins. Experimental methods to define the state of the reacting molecules, combined with detailed kinetic analysis and theory, will be used to explain the principal contributions of the interactions and the confinement to determine reaction rates. We will discuss how reaction rates and pathways can be tailored using the space available for a transition state and the chemical constituents around the active site.

A model is presented for the mechanics of deep earthquakes occurring at 400-700 kms under the surface of the earth where pressures are as high as a million atmospheres. This has been considered a mystery in geophysics. The model is based on the dynamic Eshelby inclusion problem, which is a self-similarly expanding ellipsoidal region with phase change (change in density and/or change in moduli) under prestress. In self-similar expansion, the Cauchy-Kowalewski theorem dictates zero particle velocity in the interior domain while Noether’s theorem dictates that the self-similar shape shall be one that extremizes (minimizes for stability) the energy rate required to move the phase boundary of discontinuity (dynamic J integral). This is done with the expression allowing the possibility of symmetry breaking, and with the region of phase change assuming a planar disk shape (”pancake”) (consistent with observations in nature). Due to this symmetry breaking, the 3D change of density propagating planarly induces unequal eigenstrains in the disk that may be misinterpreted as anisotropy in the moment tensor (Markenscoff, 2019). Moreover, due to the change of density squeezed to propagate planarly, the induced unequal eigenstrains (yielding deviatoric components) produce compensated linear vector dipoles (CLVDs) from which follows a second symmetry. This breaks an otherwise isotropic medium with change in density in which the direction of max shear (double couple DC) makes an angle with the direction of the region of change in density (CLVD) (Markenscoff and Jeanloz, in preparation). The angle depends on the change in density and Poisson’s ratio which will allow the estimation of the source magnitude from the far field data. It should be noted that following Knopoff and Randall (1970), the DC and CLVD are taken in seismology to have parallel axes. Thus, the seismological measurements’ interpretation will need to be reconsidered in view of the angle between DC and CLDV radiations.

An elastic constitutive model of gravity where we identify physical space with the mid-hypersurface of an elastic hyperplate called the “cosmic fabric” and spacetime with the fabric’s world volume. Using a Lagrangian formulation, we show that the fabric’s behavior as derived from Hooke’s Law is analogous to that of spacetime per the Field Equations of General Relativity (GR). The study is conducted in the limit of small strains, or analogously, in the limit of weak and nearly static gravitational fields. The Fabric’s Lagrangian outside of inclusions is shown to have the same form as the Einstein–Hilbert Lagrangian for free space. Properties of the fabric such as strain, stress, vibrations and elastic moduli are related to properties of gravity and space, such as the gravitational potential, gravitational acceleration, gravitational waves and the energy density of free space. By introducing a mechanical analogy of GR, we enable the application of Solid Mechanics tools to address problems in Cosmology. Finally, because the cosmos acts as a continuum body with external tractions according to Cauchy’s Law, the existence of God is proven as exemplified by the tractions on the outside surface of the cosmos.

The reaction of CO₂ hydrogenation is of high environmental interest since it allows for the transformation of the logistically challenging H₂, gained from renewable sources, to the much more manageable hydrocarbons.
CO₂ hydrogenation takes place mainly through the following two reactions:
xCO₂ + (2x-z+y/2)H₂ --> C_xH_xO_z + (2x-z)H₂O
and
CO₂ + H₂ --> CO + H₂O
The first reaction directly produces hydrocarbons whereas the second one, also known as RWGS, produces syngas which is useful in the synthesis of several hydrocarbons.
With CO₂ being a rather inert molecule, the reaction of CO₂ hydrogenation requires high pressures and temperatures, as well as the existence of a good catalyst. The development of an efficient catalyst is a requirement for the extensive application of a strategy where renewable energy is stored as HCs. An important parameter for the development of an efficient catalyst is the metal-support interactions. Those interactions have been closely identified as the underlying reason for Electrochemical Promotion of Catalysis [1-5]. Conversely, EPOC has proven itself as a valuable tool for the study of metal support interactions. Promoters of catalysts alter the catalytic activity and selectivity by modifying the bonds of the reactants on the active sites and the work function of the catalytic surface. Electropositive promoters enhance the chemisorption of electron-acceptors and weaken the bonds of electron donors. Electronegative promoters have the opposite effect [1-5]. Ruthenium is a catalyst widely used to produce methane from CO₂. In this study, we present an example of how electrochemical promotion of catalysis (EPOC) can elucidate the role of solid electrolytes (YSZ, BZY), supporting Ru porous films or nanoparticles.
The results of the study have shown that the electrolytic features of the support (anionic or cationic or mixed conductor) can have a very pronounced and dominant effect on the activity and selectivity of the supported metal nanoparticles. The mechanism of the interaction can be studied conveniently via EPOC and then the support can be chosen accordingly. Nucleophilic EPOC behavior suggests that the reaction will be enhanced when using an anionic catalyst support, such as YSZ, and electrophilic EPOC behavior suggests that the reaction will be enhanced using a cationic support, such as BZY. Thus, one may conclude, again, that EPOC (or NEMCA effect) and MSI are functionally identical and only operationally different [1, 2] since they both rely on ion spillover. The use of EPOC can significantly facilitate the choice of catalyst support.

High quality H₂ can be produced through water electrolysis at low or high temperatures. In this respect, solid oxide electrolysis cells (SOECs) are a promising and fast growing technology [1, 2] for H₂O electrolysis above 500°C. SOECs have identical configuration with SOFCs, but reverse operations and currently novel modified Ni-based fuel electrodes are under investigation for H₂O, CO₂ and H₂O⁺ CO₂ electrolysis applications [1, 3].
The presented study focuses on the effect of transition metal elements as dopants of the commercial NiO/GDC powder for the Solid Oxide H₂O electrolysis. Specifically, the experimental comparison is between Au [1], Mo and Fe doping. Comparative electrocatalytic measurements with I-V curves and electrochemical impedance spectra (EIS) analyses are presented in the range of 800-900°C between electrolyte-supported cells with Ni/GDC, 3Au-Ni/GDC [1], 3Mo-Ni/GDC, 3Au-3Mo-Ni/GDC, 2Fe-Ni/GDC and 0.5Fe-Ni/GDC, as the fuel electrode. Complementary physicochemical characterization was also performed both in the form of powders and as half cells with ex-situ and in-situ techniques, including specific redox stability measurements in the presence of H₂O.
In summary, the cell comprising the ternary 3Au-3Mo-Ni/GDC electrode and that with 0.5Fe-Ni/GDC performed significantly better compared to the rest. The superior performance of the ternary sample is primarily ascribed to the enrichment of the surface with Au [1] and of the bulk phase with Mo, through the formation of Ni-Au-Mo solid solution [3, 4]. The involved elements act in synergy and modify the physicochemical properties of the electrode, improving the: (i) H₂O re-oxidation rate, (ii) electronic conductivity and (iii) electrochemical interface. In regards to Fe-doping, the wt.% content in iron is one key parameter. The 0.5wt.% loading of Fe results in an electrode of similar high performance to that of the Au-Mo-Ni electrode, having the great advantage of not containing gold in its composition.

The post-Minkowskian approximation of the N-body problem of general relativity has been recently analysed by Luc Blanchet and the speaker[1]. The ultrarelativistic limit of the above formulation in the particular case of two equal masses yields a formula for the underlying force which has characteristics of the strong force, including confinement and asymptotic freedom[2]. This result is consistent with the iconoclastic model of particle physics of C Vayenas.