CO electroreduction performance of a single transition metal atom supported on porphyrin-like graphene: a computational study.

Searching for low-cost, efficient, and stable electrocatalysts for CO electroreduction (COER) reactions is highly desirable for the reduction of CO emission and its conversion into useful products, but remains a great challenge. In this work, single transition metal atoms supported on porphyrin-like graphene catalysts, i.e., TMN/graphene, acting as electrocatalysts for CO reduction were explored by means of comprehensive density functional theory (DFT) computations. Our results revealed that these anchored TM atoms possess high stability due to their strong hybridization with the unsaturated N atoms of the substrate and function as the active sites. On the basis of the calculated adsorption strength of COER intermediates, we have identified that single Co, Rh, and Ir atoms exhibit superior catalytic activity towards CO reduction. In particular, CHOH is the preferred product of COER on the CoN/graphene catalyst with an overpotential of 0.59 V, while the RhN/graphene and IrN/graphene catalysts prefer to reduce CO to CHO with an overpotential of 0.35 and 0.29 V, respectively. Our work may open a new avenue for the development of catalytic materials with high efficiency for CO electroreduction.