Optimizing CO production in electrocatalytic CO2 reduction via electron accumulation at Ni sites in Ni3ZnC0.7/Ni on N-doped carbon nanofibers

The electrocatalytic reduction of carbon dioxide (CO 2 RR) to valuable products presents a promising solution for addressing global warming and enhancing renewable energy storage. Herein, we construct a novel Ni 3 ZnC 0.7 /Ni heterostructure electrocatalyst, using an electrospinning strategy to prepare metal particles uniformly loaded on nitrogen-doped carbon nanofibers (CNFs). The incorporation of zinc (Zn) into nickel (Ni) catalysts optimizes the adsorption of CO 2 intermediates, balancing the strong binding affinity of Ni with the comparatively weaker affinity of Zn, which mitigates over-activation. The electron transfer within the Ni 3 ZnC 0.7 /Ni@CNFs system facilitates rapid electron transfer to CO 2 , resulting in great performance with a faradaic efficiency for CO (FE CO ) of nearly 90% at −0.86 V versus the reversible hydrogen electrode (RHE) and a current density of 17.51 mA cm −2 at −1.16 V versus RHE in an H-cell. Furthermore, the catalyst exhibits remarkable stability, maintaining its crystal structure and morphology after 50 h of electrolysis. Moreover, the Ni 3 ZnC 0.7 /Ni@CNFs is used in the membrane electrode assembly reactor (MEA), which can achieve a FE CO of 91.7% at a cell voltage of −3 V and a current density of 200 mA cm −2 at −3.9 V, demonstrating its potential for practical applications in CO 2 reduction. • Heterostructured Ni 3 ZnC 0.7 /Ni@CNFs for CO 2 electroreduction has been synthesized via electrospinning. • The electron transfer within Ni 3 ZnC 0.7 /Ni @CNFs facilitates rapid electron transfer to CO 2 . • The interface effect of Ni and Zn atoms optimizes the adsorption of ∗COOH. • Ni 3 ZnC 0.7 /Ni@CNFs exhibited remarkable stability and catalytic performance. • MEA setup achieved a FE CO of 91.7 % at 3 V and 200 mA cm −2 at 3.9 V.