Mechanistic insight into the C1 product selectivity for the catalytic hydrogenation of CO2 over metal-doped graphene

Abstract The conversion of CO 2 into fuels and valuable chemicals presents a viable path toward carbon neutrality. The aim of this study is to investigate the potential of metal-doped graphene catalysts in the reduction of CO 2 to C 1 products. 20 typical M-graphene (M = metal) catalysts were established based on DFT calculations. Six candidate catalysts, i.e., V-, Cr-, Mn-, Ni-, Mo-, and Ta-graphene catalysts, were selected by combining the hydrogen dissociation ability and the energy band gap of the catalysts. Subsequently, the adsorption characteristics and hydrogenation reactions of CO 2 over the six candidates were explored. CO 2 tends to adsorb at the M site through vertical adsorption and carbon–oxygen co-adsorption. V- and Cr-graphene catalysts promote the production of intermediate COOH, whereas Mn-, Ni-, Mo-, and Ta-doped surfaces are more favorable for HCOO formation. Concerning the hydrogenation to CO and HCOOH, V-, Cr-, Ni- and Mo-graphene catalysts preferentially yield CO from COOH, whereas Ta-doped graphene favors the formation of HCOOH. In total, the competitive hydrogenation of CO 2 reveals the selectivity of the C 1 products. Cr- and Ni-graphene favor the production of HCOOH and CH 3 OH, whereas V-, Mn-, Mo-, and Ta-graphene primarily yield CH 3 OH. Graphical Abstract