Cu-Ni Alloy Nanoparticles Anchored on Nitrogen-Doped Carbon Nanotubes for Efficient CO2 Electroreduction to CO

Efficient conversion of CO2 to value-addedfuels orchemicals using electricity from renewable sources is an appealingapproach to realize carbon neutrality. Under this background, it iscrucial to design efficient and low-cost catalysts for CO2 electroreduction. Herein, we fabricated an electrocatalyst withthe structure of Cu-Ni alloy nanoparticles grown on nitrogen-dopedcarbon nanotubes (Cu x Ni/NCNT, x = 2.4, 1, and 0.36) for electrochemical CO2 reduction reaction (CO2RR) via a hydrothermal methodfollowed by pyrolysis. The optimized CuNi/NCNT demonstrates a favorableCO(2)RR performance with a CO Faradaic efficiency (FECO) of 94.8% and a current density of 26.6 mA cm(-2) at -0.9 V versus the reversible hydrogen electrode (vs RHE)in the H-cell, far superior to those of single metal counterparts.Density functional theory (DFT) calculations unravel that the Cu-Nialloys possess much lower free energy changes for the formation ofthe key COOH* intermediate than those of the Cu metal, thereby facilitatingCO(2) reduction into CO. Additionally, the CO2RR performance of CuNi/NCNT was further evaluated in the gas diffusionelectrode (GDE) involved in the flow cell to examine the practicalapplication of the prepared catalyst, which can deliver a currentdensity of 124.6 mA cm(-2) with a FECO of92.8% at -1.1 V vs RHE. This work enriches electrocatalystsfor highly efficient CO2 electroreduction to CO.

Automated summary

An efficient electrocatalyst, Cu-Ni alloy nanoparticles grown on nitrogen-doped carbon nanotubes, was prepared for electrochemical CO2 reduction. The optimized catalyst showed a high CO Faradaic efficiency of 94.8% and a current density of 26.6 mA cm(-2). This work enriches the research on highly efficient CO2 electroreduction catalysts.