CO2 electro-reduction reaction via a two-dimensional TM@TAP single-atom catalyst

In this study, the possibility of using TM atom anchored monolayer TAP as a class of electrocatalysts (TM@TAP, TM = 3d and 4d transition metal) toward carbon dioxide reduction reaction (CO2RR) was systematically investigated using first-principles calculations. During screening potential catalysts, the possibility that H and OH block the active site was considered. Then, the reaction mechanisms of screened catalysts were explored in detail. Interestingly, the different catalysts demonstrated different selectivities. Our results demonstrate that Cr@TAP, Zn@TAP, Mo@TAP, and Cd@TAP are selective toward the HCOOH product with a limiting potential in the range of -0.33 to -0.71 V. Mn@TAP and Rh@TAP promote CO production. The reduction products of Fe@TAP and Co@TAP were CH3OH and HCHO, respectively. Tc@TAP and Ru@TAP can catalyze CO2 to yield the deep reduction product, i.e. CH4. Among these catalysts, Cr@TAP and Rh@TAP are highly active due to their lower limiting potentials of -0.33 V and -0.28 V, respectively, and Fe@TAP can promote the production of the desired CH3OH with a limiting potential of -0.51 V, which allow them to be promising electrocatalysts for the CO2RR. We hope that our study will provide some insights into the rational design of electrocatalysts and useful guidance for experimental researchers.