2018 - Sustainable Industrial Processing Summit & Exhibition
4-7 November 2018, Rio Othon Palace, Rio De Janeiro, Brazil
| A Combined SERS-DFT Study Towards Deep Understanding Electrocatalysis Zhongqun Tian1; Yi-fan Huang2; Christian Amatore3; An Wang2; De-yin Wu2; Sandra Rondinini4; 1DEPARTMENT OF CHEMISTRY, XIAMEN UINVERSITY, Xiamen, China; 2XIAMEN UNIVERSITY, Xiamen, China; 3CNRS & PSL, FRENCH ACADEMY OF SCIENCES, Paris, France; 4UNIVERSITA DEGLI STUDI DI MILANO, Milan, Italy; PAPER: 277/Electrochemistry/Plenary (Oral) SCHEDULED: 11:20/Mon./Copacabana B (150/1st) ABSTRACT: Surface-enhanced Raman spectroscopy (SERS) is one of the few powerful in-situ electrochemical spectroscopies, since it is highly sensitive on the surface species and almost inert on the species in the bulk of electrolyte. However, in order to comprehensively understand electrocatalysis, EC-SERS has to be correctly understand and consistent with the electrochemistry and theory. Here, we present the EC-SERS study on the electrocatalytic reduction of benzyl chloride on Ag by combing experiments and theoretical calculations. To identify the electrode surface species, we performed DFT calculations with Raman spectroscopy on the possible reaction intermediates and products. The results show that the Raman spectrum of the negatively charged benzyl-Ag cluster shows similar spectroscopic characters as experimental spectra, which indicates benzyl anion adsorbed Ag electrode is the key intermediate of the electrocatalytic reduction of benzyl chloride on Ag. By applying the same strategy, we also studied the adsorption of benzyl chloride and the possible products. In light of the reaction pathway roughed out by the consistent EC-SERS observations and DFT simulations on the spectra, the details of the electrocatalysis regarding the binding energy and the activation energy of reactants and intermediates are revealed by electrochemical kinetics calculation combined with DFT calculation. We found that the weakly interaction between distorted benzyl chloride anion and Ag facilitates the dissociation of C-Cl bond and drives the conversion of benzyl chloride. The more detailed discussion will be given. The combined EC-SERS/DFT investigation provides a key entry for understanding the origin of electro-catalytic activity by consistent experimental observations and theoretical calculations. References: [1] A. Wang, Y. F. Huang, U. K. Sur, D. Y. Wu, B. Ren, S. Rondinini, C. Amatore, Z. Q. Tian, J. Am. Chem. Soc. 132(2010)9534-9536. [2] Y. F. Huang, D. Y. Wu, A. Wang, B. Ren, S. Rondinini, Z. Q. Tian, C. Amatore, J. Am. Chem. Soc. 132(2010)17199-17210. |
