The Screening of Homo‐ and Hetero‐Dual Atoms Anchored Graphdiyne for Boosting Electrochemical CO2 Reduction

Developing electrocatalysts with high catalytic performance and selectivity is crucial for electrochemical CO2 reduction reaction (CRR). There are many catalyst studies of transition metal (TM) atom doping to sp2 carbon material, such as graphene or carbon nanotubes. On the other hand, graphdiyne (GDY) has both sp and sp2 hybridization and stable pores, so we can tune its interaction with TM. Following the successful experimental synthesis of Ni atom doping to GDY monolayer, the CRR activity of double–atom catalysts was evaluated, including homo and hetero metal-Ni doped on the GDY monolayer (MNi@GDY where M is Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) using the density functional theory calculations. The valence-electron number of the catalytic center shows a strong positive correlation to the limiting potentials in the volcano plot. NiNi@GDY is the most promising candidate for converting CO2 to produce CH4 with a remarkable low limiting potential of −0.28 V, which is better than Ni@GDY and Ni3@GDY counterparts. NiNi@GDY shows excellent thermal stability and ability to suppress the competing hydrogen evolution reaction, showing its high selectivity to CH4.