First-Principles Investigation of Promoting Effect in CO_2 Methanation with an Electric Field in SOEC

摘要

Non-faradaic electrochemical modification of catalytic activity (NEMCA) by impression of electric field is one of the methods to improve catalyst performance. In this study, we have theoretically investigated the mechanism of NEMCA in CO_2 methanation in solid oxide electrolysis cell using the density functional theory (DFT). DFT calculations have been performed for hydrocarbon species on Ni (111) facet with direct electric field or co-adsorbed oxygen atoms, and their dependence for the rate determining steps (RDSs) in CO_2 methanation from our kinetic simulation has discussed. We have found that direct effects of electric field in surfaces adsorption are different in each intermediate in RDSs and all RDSs accelerate with electric field. While, all intermediates bind on the surface less strongly as increasing the number of co-adsorbed oxygen atoms and some reactions decelerate and the other accelerate with co-adsorbed oxygen atoms.