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

•FeNi@N-CNTs-1100 exhibits an excellent CO2-to-CO conversion performance.•High CO FE of 97.8 % and long-term stability of 35 h at low overpotential of –0.77 vs. RHE.•CO FE over 90 % in a wide potential range of –0.47 to –0.97 and high jCO of 20.18 mA cm−2 at –0.97 V.•Synergistic effect of the N species on N-CNTs and FeNi alloy NPs generates more optimal *COOH adsorption and *CO desorption.