关键词:  氮化钴, 二氧化碳电还原, 一氧化碳, 合成气

Abstract:

Electrocatalytic reduction of carbon dioxide (CO₂) is a promising method to alleviate global warming issues, although it still faces many challenges. Herein, we report cobalt nitride for electrocatalytic reduction of CO₂ to carbon monoxide (CO) in an aqueous electrolyte. A comparison of catalysts with different preparation temperatures and atmospheres suggests that nitrogen doping is critical to improve catalytic activity. For the most active catalyst of 700-Co_5.47N/C, the CO current density reached 9.78 mA·cm^-2 at potential of -0.7 V vs. RHE. In addition, the CO/H₂ ratio could be adjusted from 1:3 to 3:2 by changing applied potential. Tafel slope of 91 mV·dec^-1 indicates that forming a surface adsorbed CO2·- intermediate became the rate-determining step and nitriding strategy increased CO₂ selectivity by providing more base sites.

Key words: cobalt nitride, carbon dioxide electroreduction, carbon monoxide, syngas