FeNi alloys encapsulated with N-doped porous carbon nanotubes as highly efficient and durable CO2 reduction electrocatalyst

The development of highly efficient, cost-effective, and robustly stable electrocatalysts for CO2 reduction remains a significant challenge. In this study, a promising CO2 reduction electrocatalyst composed of nanostructured transition metal alloys (i.e., FeNi, FeCo, or CoNi) nanoparticles encapsulated on N-doped porous carbon material is reported. Among the different compositions, FeNi@N-CNTs-1100 exhibited the most efficient CO2ER activity and exceptional stability. It demonstrated a high CO Faradaic efficiency of over 90 % in a wide potential range (–0.47 to –0.97 V (vs. RHE)), with a CO partial current density of 20.18 mA cm−2 at –0.97 V (vs. RHE). Notably, it achieved a long-term stability of 35 h at –0.77 V (vs. RHE) in an H-cell with 0.5 M KHCO3 electrolyte. Various characterization techniques and designed experiments revealed that FeNi@N-CNTs-1100 exhibited enhanced intrinsic catalytic activity and CO selectivity due to optimized *COOH adsorption and *CO desorption compared to the other catalysts studied.