Single Co atoms anchored on nitrogen-doped hierarchically ordered porous carbon for selective hydrogenation of quinolines and efficient oxygen reduction

Abstract

Constructing ordered macro-mesoporous carbon with nonprecious metal single-atom sites to improve the utilization rate of the inaccessible active sites inside the carbon can significantly facilitate its catalytic performance and reduce costs. Herein, by elaborate design, we pyrolyze ordered macro-microporous bimetallic single-crystalline ZnCo-ZIFs to fabricate single Co atoms anchored on N-doped hierarchically ordered porous carbon (Co-SAs@NHOPC) that showed an excellent yield of 99% and outstanding selectivity of > 99% for quinolines hydrogenation reaction (QHR). Besides, the obtained Co-SAs@NHOPC also exhibited excellent performance for the oxygen reduction reaction (ORR) in 0.1 M KOH with a half-wave potential of 0.851 V versus reversible hydrogen electrode (RHE). The as-obtained Co-SAs@NHOPC structure is the exquisite integration of the three-dimensional (3D) bicontinuous porous frameworks, the inherited micropores within N-doped carbon skeletons, well-defined tetrakaidecahedron morphology, and atomically dispersed Co atoms. The 3D hierarchical porous characteristics allow the reactants to contact the active sites inside the N-doped carbon and improve the mass transfer efficiency, thereby improving the atom utilization rate for QHR and ORR.