DFT study the water-gas shift reaction over Cu/α-MoC surface

Cu-based catalysts have been widely used for water-gas shift reaction (WGS, CO + H2O -> CO2 + H-2), and alpha-MoC support also shows the good performance for the reaction. Therefore, WGS reaction is systematically studied over Cu/alpha-MoC by using density functional theory (DFT). DFT result shows the strong metal-support interaction between Cu and alpha-MoC(111) support. As a result, an extensive tensile strain is introduced in the Cu lattice due to alpha-MoC support, and Cu 3d band center shifts to Fermi level. However, the strong metal-support interaction does not lead to significant polarization of the Cu/alpha-MoC surface due to the less charge transfer from Mo to Cu. For the WGS reaction, small Cu particles on alpha-MoC(111) are likely to facilitate the reaction. At the interface of Cu-alpha-MoC(111), oxygen stabilizes the dissociated *H, which is benefit of H2O scission. Then, the activity increases compared with Cu(111) surface. In general, small Cu particles on alpha-MoC support also have good activity for WGS reaction compared with Au deposition on alpha-MoC.