Regulating Efficient and Selective Single-atom Catalysts for Electrocatalytic CO Reduction.

Anchoring transition metal (TM) atoms on suitable substrates to form single-atom catalysts (SACs) is a novel approach to constructing electrocatalysts. Graphdiyne with sp-sp hybridized carbon atoms and uniformly distributed pores have been considered as a potential carbon material for supporting metal atoms in a variety of catalytic processes. Herein, density functional theory (DFT) calculations were performed to study the single TM atom anchoring on graphdiyne (TM -GDY, TM=Sc, Ti, V, Cr, Mn, Co and Cu) as the catalysts for CO reduction. After anchoring metal atoms on GDY, the catalytic activity of TM -GDY (TM=Mn, Co and Cu) for CO reduction reaction (CO RR) are significantly improved comparing with the pristine GDY. Among the studied TM -GDY, Cu -GDY shows excellent electrocatalytic activity for CO reduction for which the product is HCOOH and the limiting potential (U ) is -0.16 V. Mn -GDY and Co -GDY exhibit superior catalytic selectivity for CO reduction to CH with U of -0.62 and -0.34 V, respectively. The hydrogen evolution reaction (HER) by TM -GDY (TM=Mn, Co and Cu) occurs on carbon atoms, while the active sites of CO RR are the transition metal atoms . The present work is expected to provide a solid theoretical basis for CO conversion into valuable hydrocarbons.