Catalysis Letters, Vol.148, No.6, 1686-1691, 2018
CO2 Activation on Cobalt Surface in the Presence of H2O: An Ambient-Pressure X-ray Photoelectron Spectroscopy Study
Co-based catalysts for CO2 reduction to liquid fuels have been attracting increasing attention. In this work, the distribution of surface intermediates on a polycrystalline Co foil was investigated by ambient-pressure X-ray photoelectron spectroscopy (APXPS) experiments under near ambient pressure and temperature conditions. The Co surface was partially oxidized, predominantly by carbonates, after CO2 dissociative adsorption. Graphitic carbon deposition on the partially oxidized Co surface was significantly lesser than that on the open surfaces of Cu and Ni under similar reaction conditions. Methoxy, formate, and a bulk carbonate formed upon the co-adsorption of H2O with a surprisingly high methoxy/formate coverage ratio. These results provide valuable mechanistic information for developing highly selective Co-based catalysts for CO2 reduction. [GRAPHICS] .