Bimetallic Cobalt-Copper Nanoparticle-Decorated Hollow Carbon Nanofibers for Efficient CO₂ Electroreduction

Bimetallic materials are one of the most promising catalysts for the electrochemical reduction of CO₂, but there are still many challenges to be overcome on the route to industrialization. Herein, a series of carbon nanofiber-supported bimetallic cobalt-copper catalysts (Co_xCu_y/CFs) are designed and constructed through the electrospinning technique and a subsequent pyrolysis procedure. Small-sized Co-Cu nanoparticles are homogenously distributed on the porous carbon nanofibers, which can significantly improve the utilization rate of metal sites and greatly reduce the loading amount of metals. Moreover, different product distributions and catalytic performance can be obtained in CO₂ reduction via adjusting the metal proportion of Co_xCu_y/CFs. Especially, Co₃Cu/CFs can bring forth a 97% total faradaic efficiency (FE) of CO (68%) and HCOOH (29%) at -0.8 V_RHE cathode potential in 0.5 M KHCO₃ electrolyte. Furthermore, the hierarchical pores can firmly confine the small Co-Cu nanoparticles and keep them from easy agglomeration during electrolysis, eventually leading to 60 h of stability for Co₃Cu/CFs in CO₂ electroreduction. This study might provide a facile and economic method to fabricate efficient bimetallic catalysts for CO₂ electroreduction and other electrocatalysis applications.