Metal-free Catalyst B2 S Sheet for Effective CO2 Electrochemical Reduction to CH3 OH.

Considering the problems of high costs, low catalytic activity and selectivity in the metal-based catalysts for CO2 electroreduction, we apply boron-containing metal-free B2 S sheet as an alternative to the traditional metal-based catalysts. Reaction energy calculations identify the preferred "Formate" pathway for CO2 conversion to CH3 OH on B2 S, in which the thermodynamic energy barrier obtained by using the Computational Hydrogen Electrode model is 0.57 eV, and the kinetic energy barrier obtained by searching the transition states is 1.18 eV. Another possible reaction pathway, "RWGS+CO-hydro", is suppressed and the hydrogen evolution reaction (HER) side reaction is nonspontaneous. Compared to Cu(211) with the highest catalytic activity among all transition metals, B2 S sheet exhibits a better catalytic activity with a lower overpotential for CO2 reduction and a better selectivity that suppresses the non-target reaction.