A robust Ni@NCNT-C catalyst for highly efficient electrochemical CO2 reduction to CO over a wide potential range

Abstract

The electrochemical CO2 reduction reaction (CO2RR) to CO is regarded as a potential way to relieve CO2 level and produce value-added chemicals. However, most reported catalysts only possess high Faraday efficiency of CO (FECO%) under a narrow potential range, and this shortage largely limits its ultimate practical viability. Herein, we develop a facile method to synthesize nickel encased by nitrogen-doped carbon nanotubes on carbon support (Ni@NCNT-C) catalyst for CO2RR. As for the important influence factors, the Ni content and treatment temperature are carefully controlled, and their influence on textural property and catalytic performance is investigated. The 0.1Ni@NCNT-C-800 catalyst provides a low overpotential (−0.27 V vs. RHE) and high FECO% (∼100%). The CO partial current density can reach 230 mA cm−2 and the activity can be maintained over 40 h. More importantly, a wide potential range of 900 mV (−0.27 V to − 1.17 V vs. RHE) can be obtained when FECO% is continuously maintained at nearly 100%. This work may provide a route to seek a robust catalyst for high-efficiency CO2RR over a wide potential range.