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

We develop an N-coordination strategy to design a robust CO 2 reduction reaction (CO 2 RR) electrocatalyst with atomically dispersed Co–N 5 site anchored on polymer-derived hollow N-doped porous carbon spheres. Our catalyst exhibits high selectivity for CO 2 RR 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–N 5 site is the dominating active center simultaneously for CO 2 activation, the rapid formation of key intermediate COOH* as well as the desorption of CO.