Facile synthesis of single-nickel-atomic dispersed N-doped carbon framework for efficient electrochemical CO₂ reduction

While converting carbon dioxide (CO₂) into value-added carbon products by electrolyzing offers a promising approach to mitigate global warming and store energy, poor selectivity and stability of catalysts still impede this conversion. Single-atom catalyst exhibits exceptional selectivity for CO₂ electroreduction reaction in response to inhibiting hydrogen evolution reaction (HER), which is the major obstacle to the development of CO₂ reduction. Herein we introduce a facile approach to obtain Ni-Nx sites encapsulating into carbon nanotubes with a nickel loading as high as 6.63 wt%. This catalyst exhibits high Faradaic efficiency approximately 95% for CO₂ electroreduction to carbon monoxide (CO) in the wide potential range from −0.7 to −1.0 V, and the current density reaches 57.1 mA cm⁻² at −1.0 V versus a reversible hydrogen electrode (RHE). Experiments and characterization results demonstrate that nickel chemical state and content play a vital role for CO₂ electrocatalytic performance. Moreover, the simplifying of the synthesis may shed a new light on design single atom catalysts of electrochemistry in addition to CO₂ reduction.