Rare Earth Metal Anchored into Nitrogen-Doped Graphene for CO Electrocatalytic Reduction to C1 Products.

Single-atom catalysts (SACs) are attracting global attention due to their 100% atomic utilization rate and unique properties. Rare-earth-based SACs have shown great potential in the field of electrocatalysis in recent years. In this study, the catalytic performance of four rare earth metals (REMs) anchored into N-graphene for the CORR is systematically studied by density functional theory. The calculation results of formation energy show that all REM@N-G compounds have favorable stability. In addition, the Gibbs free energy calculation results of all possible elementary reactions show that the *OCHO pathway is the optimal hydrogenation pathway for all catalysts, and they have the same potential determining step (*OCHO + e + H → *HCOOH). Meanwhile, the products of the CORR on these catalysts are different, and the product on REM@N-G (REM = La, Pr, and Nd) is CH, while the product on Ce@N-G is CHOH. In particular, Nd@N-G exhibits the best catalytic activity in this work, with a very low limiting potential of -0.38 V. These results may guide the development of rare-earth-based SACs for CORR.