Synergistic Interaction between the Ni-Center and Glycine-Derived N-Doped Porous Carbon Material Boosts Electrochemical CO₂ Reduction

Electrochemical conversion of CO2 into CO is highly attractive since CO is highly valuable for its wide use in organic synthesis as well as a fuel-type molecule. However, the selective formation of CO from CO2 is highly sensitive to the variation of particle size, coordination number, and defects in the electrocatalyst. Considering this, we report a boosted electrochemical CO2 reduction performance on a Ni, N-codoped hierarchical porous carbon material (Ni@MicroPNC) by exposing substantial active sites during the carbonization process by using ZnCl2 as the porous template agent due to its relatively low boiling point. A particular advantage of our electrocatalyst is that the support (N-doped hierarchical porous carbon material) of the Ni-catalyst is synthesized by using glycine as a carbon precursor. To our observation, the as-prepared Ni@MicroPNC catalyst displayed a high CO faradaic efficiency (FE) of 92.8% with a high partial current density (jco) of 22.4 mA cm–2 and outstanding current density stability at −0.81 V (vs RHE) for 10 h. The suggested high CO selectivity and catalytic stability of Ni@MicroPNC are attributed to the synergistic effect of high specific surface area, optimized hierarchical structure, Ni, N codoping into the porous carbon material, and relatively weaker CO binding strength. Furthermore, DFT calculations indicate that the doped N atom interacted with the Ni center to lower the energy barrier of *CO desorption. This finding provides a facile strategy for the synthesis of low-cost and highly active nanoparticle-based electrocatalysts for a selective reduction of CO2 into CO.