Atomically dispersed Ni species on N-doped carbon nanotubes for electroreduction of CO2 with nearly 100% CO selectivity

Abstract

It is imperative to develop efficient and robust electrocatalysts for CO2 reduction reaction (CO2RR) that would overcome the sluggish kinetics and exhibit high current density. Porous carbon nanotubes with highly delocalized electrons and tubular structure are promising candidates for CO2RR due to it is favorable for the accessible of substrates to active sites. However, there are rare reports of using carbon nanotubes to stabilize single-atom active sites for CO2RR. Herein, a self-sacrificial template method is developed to disperse single atomic Ni sites on N-doped carbon nanotubes from metal-organic frameworks (MOFs) for highly efficient CO2RR. Compared with the corresponding other N-doped carbon stabilized Ni single-atom catalysts, the obtained hierarchically porous Ni/NCTs exhibited enhanced selectivity and activity for the electrochemical reduction of CO2 to CO with Faradaic efficiency of 98 %, turnover frequency (TOF) of 9366 h−1 and CO current density of 34.3 mA cm-2 at the applied potential of -1.0 V.