Highly Boosted Reaction Kinetics in Carbon Dioxide Electroreduction by Surface‐Introduced Electronegative Dopants

Abstract

AbstractEffectively improving the selectivity while reducing the overpotential over the electroreduction of CO2 (CO2ER) has been challenging. Herein, electronegative N atoms and coordinatively unsaturated NiN3 moieties co‐anchored carbon nanofiber (NiN3NCNFs) catalyst via an integrated electrospinning and carbonization strategy are reported. The catalyst exhibits a maximum CO Faradaic efficiency (F.E.) of 96.6%, an onset potential of −0.3 V, and a low Tafel slope of 71 mV dec−1 along with high stability over 100 h. Aberration corrected scanning transmission electron microscopy, X‐ray absorption spectroscopy, and X‐ray photoelectron spectroscopy identify the atomically dispersed NiN3 sites with Ni atom bonded by three pyridinic N atoms. The existence of abundant electronegative N dopants adjoin the NiN3 centers in NiN3NCNFs. Theoretical calculations reveal that both, the undercoordinated NiN3 centers and their first neighboring C atoms modified by extra N dopants, display the positive effect on boosting CO2 adsorption and water dissociation processes, thus accelerating the CO2ER kinetics process. Furthermore, a designed ZnCO2 battery with the cathode of NiN3NCNFs delivers a maximum power density of 1.05 mW cm−2 and CO F.E. of 96% during the discharge process, thus providing a promising approach to electric energy output and chemical conversion.