ORALS
SESSION: PhysicalThuAM-R10
| Vayenas International Symposium on Physical Chemistry and its applications for sustainable development |
Thu Oct, 24 2019 / Room: Aphrodite B (100/Gr. F) | |
Session Chairs: Antonio de Lucas Consuegra; Dimitrios Niakolas; Session Monitor: TBA |
11:20: [PhysicalThuAM01] Plenary
Neutrinos and Electrons/Positrons: The Building Elements and Catalysts of our Universe Constantinos
Vayenas1 ;
1University of Patras, Patras, Greece;
Paper Id: 353
[Abstract] 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<sub>e</sub>+e<sup>+</sup> → 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.
References:
[1] D. Griffiths, Introduction to Elementary Particles. (2nd ed. Wiley-VCH Verlag GmbH & Co. KgaA, Weinheim, 2008).\n[2] C. G. Vayenas, S. N.-A. Souentie, Gravity, special relativity and the strong force: A Bohr-Einstein-de Broglie model for the formation of hadrons. (Springer, NY, 2012).\n[3] C.G. Vayenas, S. Souentie, A. Fokas, “A Bohr-type model of a composite particle using gravity as the attractive force”. Physica A, 405, 360-379 (2014).\n[4] C.G. Vayenas, A.S. Fokas, D. Grigoriou, “On the structure, masses and thermodynamics of the W bosons”. Physica A, 450, 37-48 (2016).\n[5] A.S. Fokas, C.G. Vayenas, “On the structure, mass and thermodynamics of the Zo bosons”. Physica A, 464, 231-240 (2016).\n[6] A.S. Fokas, C.G. Vayenas, D.P. Grigoriou, “On the mass and thermodynamics of the Higgs boson”. Physica A, 492, 737-746 (2018).\n[7] C.G. Vayenas, “Thermodynamics and catalysis of the generation of mass”, Proceedings of the Academy of Athens, 93A, 97-133 (2018).\n[8] D. Grigoriou, C.G. Vayenas, “Schwarzschild geodesics and the Strong Force” in Proc. of the 18th Lomonosov conference, in “Particle Physics at the Year of 25th Anniversary of the Lomonosov Conferences”, p. 374, (2019).\n[9] A. Fokas, “Ultra-relativistic gravity has properties associated with the strong force”, Eur. Phys. J. C, 79, 271 (2019).\n[10] C.G. Vayenas, A.S. Fokas, D. Grigoriou, “Catalysis and autocatalysis of chemical synthesis and of hadronization”. Appl. Catal. B, 203, 582-590 (2017).
SESSION: PhysicalThuPM1-R10
| Vayenas International Symposium on Physical Chemistry and its applications for sustainable development |
Thu Oct, 24 2019 / Room: Aphrodite B (100/Gr. F) | |
Session Chairs: Angelos Efstathiou; Alexandros Katsaounis; Session Monitor: TBA |
14:50: [PhysicalThuPM107] Keynote
The Role of the Promoting Ionic Species in Electrochemical Promotion and in Metal-Support Interactions. The Case of CO&lt;sub&gt;2&lt;/sub&gt; Hydrogenation on Ru Based Catalysts Dimitrios
Grigoriou1 ;
Dimitrios
Zagoraios1 ;
Alexandros
Katsaounis2 ;
Constantinos
Vayenas1 ;
1University of Patras, Patras, Greece;
2Department of Chemical Engineering, University of Patras, Patras, Greece;
Paper Id: 105
[Abstract] The reaction of CO<sub>2</sub> hydrogenation is of high environmental interest since it allows for the transformation of the logistically challenging H<sub>2</sub>, gained from renewable sources, to the much more manageable hydrocarbons.<br />CO<sub>2</sub> hydrogenation takes place mainly through the following two reactions:<br />xCO<sub>2</sub> + (2x-z+y/2)H<sub>2</sub> --> C<sub>x</sub>H<sub>x</sub>O<sub>z</sub> + (2x-z)H<sub>2</sub>O<br />and<br />CO<sub>2</sub> + H<sub>2</sub> --> CO + H<sub>2</sub>O
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.<br />With CO<sub>2</sub> being a rather inert molecule, the reaction of CO<sub>2</sub> 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 CO<sub>2</sub>. 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.<br />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.
References:
[1] C.G. Vayenas, S. Bebelis, C. Pliangos, S. Brosda, D. Tsiplakides, Electrochemical Activation of Catalysis: Promotion, Electrochemical Promotion and Metal-Support Interactions, Kluwer Academic/Plenum Publishers, New York, 2001.\n[2] P. Vernoux, L. Lizarraga, M.N. Tsampas, F.M. Sapountzi, A. De Lucas-Consuegra, J.-L. Valverde, S. Souentie, C.G. Vayenas, D. Tsiplakides, S. Balomenou, E.A. Baranova, Ionically Conducting Ceramics as Active Catalyst Supports, Chemical Reviews, 113 (2013) 8192-8260.\n[3] A. Katsaounis, Recent developments and trends in the electrochemical promotion of catalysis (EPOC), Journal of Applied Electrochemistry, 40 (2010) 885-902.\n[4] D. Tsiplakides, S. Balomenou, Milestones and perspectives in electrochemically promoted catalysis, Catalysis Today, 146 (2009) 312-318.\n[5] A. De Lucas-Consuegra, J. Gonzalez-Cobos, Y. Garcia-Rodriguez, A. Mosquera, J.L. Endrino, J.L. Valverde, Enhancing the catalytic activity and selectivity of the partial oxidation of methanol by electrochemical promotion, Journal of Catalysis, 293 (2012) 149-157.
SESSION: PhysicalThuPM2-R10
| Vayenas International Symposium on Physical Chemistry and its applications for sustainable development |
Thu Oct, 24 2019 / Room: Aphrodite B (100/Gr. F) | |
Session Chairs: Vasileios Kyriakou; Dimitrios Zagoraios; Session Monitor: TBA |
17:10: [PhysicalThuPM212]
Electrochemical Promotion of Methane Oxidation over Nanodispersed Pd/Co3O4 Catalysts Dimitrios
Zagoraios
1 ;
Dimitrios
Zagoraios2 ;
Alexandros
Katsaounis3 ; Angel
Caravaca
4 ; Ioanna
Kalaitzidou
4 ; Athanasia
Athanasiadi
5 ; Spyros
Ntais
4 ;
Philippe
Vernoux6 ;
Constantinos
Vayenas2 ;
1University of Patras, Dept. of Chemical Engineering, Patras, Greece;
2University of Patras, Patras, Greece;
3Department of Chemical Engineering, University of Patras, Patras, Greece;
4University of Lyon, Lyon, France;
5University of Patras Dept. of Chemical Enginnering, Patras, Achaia, Greece;
6University LYON 1, Lyon, France;
Paper Id: 59
[Abstract] 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 Co<sub>3</sub>O<sub>4</sub> semiconductor film. The Pd/Co<sub>3</sub>O<sub>4</sub> 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/Co<sub>3</sub>O<sub>4</sub> 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.
References:
[1] C.G. Vayenas, S. Bebelis, I.V. Yentekakis, H.G. Lintz, Catal. Today. 11 (1992) 303-438.\n[2] C.G. Vayenas, S. Bebelis, C. Pliangos, S. Brosda, D. Tsiplakides Electrochemical Activation of Catalysis: Promotion, Electrochemical Promotion and Metal-Support Interactions, Kluwer Academic/Plenum Publishers, New York, 2001.\n[3] C.G. Vayenas, J. Solid State Electrochem. 7-8 (2011) 1425-1435.\n[4] C. Jimenez-Borja, S. Brosda, F. Matei, M. Makri, B. Delgado, F. Sapountzi, D. Ciuparu, F. Dorado, J.L. Valverde, C.G. Vayenas, Appl. Catal. B Environ. 128 (2012) 48-54.
17:35 Break
SESSION: PhysicalFriAM-R10
| Vayenas International Symposium on Physical Chemistry and its applications for sustainable development |
Fri Oct, 25 2019 / Room: Aphrodite B (100/Gr. F) | |
Session Chairs: Ioannis Yentekakis; Philippe Vernoux; Session Monitor: TBA |
11:45: [PhysicalFriAM02] Keynote
Electrochemical Promotion of Catalysis: A Journey Through the Past Thirty Years Symeon
Bebelis1 ;
Constantinos
Vayenas2 ;
1Department of Chemical Engineering, University of Patras, Patras, Greece;
2University of Patras, Patras, Greece;
Paper Id: 109
[Abstract] 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<sup>2-</sup>, H<sup>+</sup>, Na<sup>+</sup>, 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].<br />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 <i>in situ</i> reversible tuning of catalyst performance, it opens up new possibilities for practical application in the fields of heterogeneous catalysis and applied electrochemistry [3-7]. <br />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.
References:
[1] C.G. Vayenas, S. Bebelis, S. Ladas, Nature 343 (1990) 625-627.\n[2] C.G. Vayenas, S. Bebelis, C. Pliangos, S. Brosda, D. Tsiplakides, Electrochemical Activation of Catalysis: Promotion, Electrochemical Promotion and Metal-Support Interactions, Kluwer Academic/Plenum Publishers, New York (2001).\n[3] C.G. Vayenas, J. Solid State Electrochem. 15 (2011) 1425-1435.\n[4] D. Tsiplakides, S. Balomenou, Catal. Today 146 (2009) 312-318.\n[5] A. Katsaounis, J. Appl. Electrochem. 40 (2010) 885-902.\n[6] P. Vernoux, L. Lizarraga, M.N. Tsampas, F.M.Sapountzi, A. De Lucas-Consuegra, J.L. Valverde, S. Souentie, C.G. Vayenas, D. Tsiplakides, S.Balomenou, E.A. Baranova, Chem. Rev. 113 (2013) 8192-8260.\n[7] A. De Lucas-Consuegra, Catal. Surv. Asia 19 (2015) 25-37.|
SESSION: PhysicalFriPM1-R10
| Vayenas International Symposium on Physical Chemistry and its applications for sustainable development |
Fri Oct, 25 2019 / Room: Aphrodite B (100/Gr. F) | |
Session Chairs: Katerina Aifantis; Eftychia Martino; Session Monitor: TBA |
15:15: [PhysicalFriPM108]
Experimental Investigation and Mathematical Modeling of Triode PEM Fuel Cells Eftychia
Martino1 ;
Alexandros
Katsaounis2 ;
Constantinos
Vayenas3 ;
1University of Patras, Dept. of Chemical Engineering, Patras, Achaia, Greece;
2Department of Chemical Engineering, University of Patras, Patras, Greece;
3University of Patras, Patras, Greece;
Paper Id: 58
[Abstract] 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 H<sub>2</sub> and with CO poisoned H<sub>2</sub> 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 H<sub>2</sub> 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.
References:
[1] S.P. Balomenou, C.G. Vayenas, Triode Fuel Cells and Batteries, J. Electrochem. Soc. 151 (2004) A1874. doi:10.1149/1.1795511.
[2] S.P. Balomenou, F. Sapountzi, D. Presvytes, M. Tsampas, C.G. Vayenas, Triode fuel cells, Solid State Ionics. 177 (2006) 2023-2027. doi:10.1016/j.ssi.2006.02.046.
[3] F.M. Sapountzi, S.C. Divane, M.N. Tsampas, C.G. Vayenas, Enhanced performance of CO poisoned proton exchange membrane fuel cells via triode operation, Electrochim. Acta. 56 (2011) 6966-6975. doi:10.1016/j.electacta.2011.06.012.
[4] E. Martino, G. Koilias, M. Athanasiou, A. Katsaounis, Y. Dimakopoulos, J. Tsamopoulos, C.G. Vayenas, Experimental investigation and mathematical modeling of triode PEM fuel cells, Electrochim. Acta. 248 (2017) 518-533. doi:10.1016/j.electacta.2017.07.168.
15:40 Break
SESSION: PhysicalFriPM2-R10
| Vayenas International Symposium on Physical Chemistry and its applications for sustainable development |
Fri Oct, 25 2019 / Room: Aphrodite B (100/Gr. F) | |
Session Chairs: Ilan Riess; Pasquale Bosso; Session Monitor: TBA |
15:55: [PhysicalFriPM209]
Computation of the Neutrino Flavor Masses via the Rotating Lepton Model of Hadrons and Bosons Dionysios
Tsousis1 ;
Constantinos
Vayenas1 ;
Dimitrios
Grigoriou1 ;
1University of Patras, Patras, Greece;
Paper Id: 65
[Abstract] 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.
References:
1. "Gravity, special relativity and the strong force: A Bohr-Einstein-de Broglie model for the formation of hadrons", Constantinos G. Vayenas, Stamatios N.-A. Souentie, Springer, NY, ISBN 978-1-4614-3935F-6 (2012). \n2. "A Bohr-type model of a composite particle using gravity as the attractive force", C.G. Vayenas, S. Souentie, A. Fokas, Physica A, 405, 360-379 (2014).\n3."On the structure, masses and thermodynamics of the W +- bosons". C.G. Vayenas, A.S. Fokas, D. Grigoriou, Physica A, 450, 37-48 (2016).
SESSION: PhysicalSatAM-R10
| Vayenas International Symposium on Physical Chemistry and its applications for sustainable development |
Sat Oct, 26 2019 / Room: Aphrodite B (100/Gr. F) | |
Session Chairs: Michael Stoukides; Costas Galiotis; Session Monitor: TBA |
12:10: [PhysicalSatAM03]
Proton Internal Pressure Distribution Suggests a Simple Proton Structure Dimitrios
Grigoriou1 ;
Eftychia
Martino2 ;
Constantinos
Vayenas1 ;
1University of Patras, Patras, Greece;
2University of Patras, Dept. of Chemical Engineering, Patras, Achaia, Greece;
Paper Id: 89
[Abstract] 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 10<sup>35</sup> 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.
References:
1. V.D. Burkert, L. Elouadrhiri & F.X. Girod, <i> Nature</i>,<b> 557</b>, 396 (2018).
2. C.G. Vayenas, S. Souentie Gravity, special relativity and the strong force: A Bohr-Einstein-de-Broglie model for the formation of hadrons. (Springer, New York, 2012).
3. C.G. Vayenas, S. Souentie, & A. Fokas, Physica A, <b>405</b>, 360 (2014).