Design of Single-Atom Co-N5 Catalytic Site: A Robust Electrocatalyst for CO2 Reduction with Nearly 100% CO Selectivity and Remarkable Stability

Abstract

We develop an N-coordination strategy to design a robust CO₂ reduction reaction (CO₂RR) electrocatalyst with atomically dispersed Co-N₅ site anchored on polymer-derived hollow N-doped porous carbon spheres. Our catalyst exhibits high selectivity for CO₂RR with CO Faradaic efficiency (FE_CO) above 90% over a wide potential range from -0.57 to -0.88 V (the FE_CO exceeded 99% at -0.73 and -0.79 V). The CO current density and FE_CO remained nearly unchanged after electrolyzing 10 h, revealing remarkable stability. Experiments and density functional theory calculations demonstrate single-atom Co-N₅ site is the dominating active center simultaneously for CO₂ activation, the rapid formation of key intermediate COOH* as well as the desorption of CO.