Effect of Cu Vacancy on Cu3Si(001) Surface for the Synthesis of SiHCl3 by Hydrogenation of SiCl4:A DFT Study

摘要

In this paper, the effect of Cu vacancy of Cu3Si(001) surface for the hydrogenation of silicon tetrachloride was systematically studied by density functional theory (DFT). The favorable adsorption sites and stable configurations of reaction species are obtained and three possible reaction paths of SiHCl3 formation were achieved by transition state search. For the perfect Cu3Si(001) surface(P), Path1 is the most favorable, with a reaction barrier of 158.15 kJ mol(-1). For both the single Cu-vacancy(SV) and double Cu-vacancy Cu3Si(001) surface(DV), Path2 is the most favorable, with the reaction barriers of 130.07 kJ mol(-1) and 124.81 kJ mol(-1), respectively. The results reflect that the activation energy of the reaction decreased significantly with the increase of Cu-vacancy on the Cu3Si(001) surface, which may be the reason for the higher catalytic activity of Cu3Si catalysts with smaller Cu-Si stoichiometric ratios. This study can provide a reasonable explanation for previously experimental observation and provide a guidance for future catalyst design.