CO2 Electroreduction Performance of Transition Metal Dimers Supported on Graphene: A Theoretical Study

Graphene-based materials are being hotly pursued for energy and environment applications. Inspired by the recent experimental synthesis of Fe2 dimer supported on graphene (He, Z.; He, K.; Robertson, A. W.; Kirkland, A. I.; Kim, D.; Ihm, J.; Yoon, E.; Lee, G.-D.; Warner, J. H. Nano Lett. 2014, 14, 3766–3772), here using large-scale screening-based density functional theory and microkinetics modeling, we have identified that some transition metal dimers (Cu2, CuMn, and CuNi), when supported on graphene with adjacent single vacancies (labeled as XY@2SV), perform better in CO2 electroreduction with reduced overpotental and enhanced current density. Specifically, Cu2@2SV is catalytically active toward CO production, similar to Au electrodes but distinct from bulk Cu; MnCu@2SV is selective toward CH4 generation, while NiCu@2SV promotes CH3OH production because of the difference in oxophilicity between incorporated Mn and Ni. The advantages of the outstanding selectivity of products, the high dispersity of spati...