Loading Single-Ni Atoms on Assembled Hollow N-Rich Carbon Plates for Efficient CO2 Electroreduction.

The rational design of catalysts' spatial structure is vitally important to boost catalytic performance through exposing the active sites, enhancing the mass transfer, and confining the reactants. Herein, a dual-linker zeolitic tetrazolate framework-engaged strategy is developed to construct assembled hollow plates (AHP) of N-rich carbon (NC), which is loaded with single-Ni atoms to form a highly efficient electrocatalyst (designated as Ni-NC(AHP)). In the carbonization process, the thermally unstable linker (5-aminotetrazole) serves as the self-sacrificial template and the other linker (2-methylimidazole) mainly serves as the carbon and nitrogen source to form hollow NC matrix. The formed Ni-NC(AHP) catalyst possesses enhanced mesoporosity and more available surface area, thus promoting mass transport and affording abundant accessible single-Ni sites. These features contribute to remarkable performance for electrochemical CO2 reduction with exceptionally high selectivity of nearly 100% towards CO in a wide potential range and dramatically enhanced CO partial current density.