Three‐dimensional ordered porous N‐doped carbon‐supported accessible Ni‐N x active sites for efficient CO 2 electroreduction

Electrocatalytic reduction of carbon dioxide (CO 2 RR) into high value‐added chemicals and fuels has been regarded as a promising approach to achieve carbon neutrality. Though nickel‐nitrogen‐carbon (Ni‐N‐C) electrocatalysts have shown superior CO 2 RR performance, the synthesis of highly effective Ni‐N‐C catalyst is still challenging. Herein, a three‐dimensional (3D) ordered porous nitrogen‐doped carbon‐supported Ni‐N x catalyst has been synthesized by direct pyrolysis of a mixture of SiO 2 , polyvinyl pyrrolidone, nickel‐phenanthroline complex, followed by the removal of the SiO 2 templates. Benefiting from the porous structure and accessible active sites, the optimized catalyst exhibits a high CO Faradaic efficiency above 85% between –0.6 and –0.9 V versus reversible hydrogen electrode (vs . RHE), and a large CO current density ( j CO ) of –16.2 mA·cm −2 at –0.8 V (vs. RHE). Density functional theory (DFT) calculations demonstrate that the Ni‐N‐C catalyst with Ni‐N x species can enhance CO 2 RR reaction dynamic process and suppress hydrogen evolution reaction, thus improving the conversion efficiency toward CO 2 RR.