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

Abstract While converting carbon dioxide (CO 2 ) 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 CO 2 electroreduction reaction in response to inhibiting hydrogen evolution reaction (HER), which is the major obstacle to the development of CO 2 reduction. Herein we introduce a facile approach to obtain Ni-N x sites encapsulating into carbon nanotubes with a nickel loading as high as 6.63 wt%. This catalyst exhibits high Faradaic efficiency approximately 95% for CO 2 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 CO 2 electrocatalytic performance. Moreover, the simplifying of the synthesis may shed a new light on design single atom catalysts of electrochemistry in addition to CO 2 reduction.