(509ad) Highly Boosted Reaction Kinetics in Carbon Dioxide Electroreduction By Surface?Introduced Electronegative Dopants | AIChE

(509ad) Highly Boosted Reaction Kinetics in Carbon Dioxide Electroreduction By Surface?Introduced Electronegative Dopants

Authors 

Zheng, W. - Presenter, Zhejiang University
Hou, Y. - Presenter, Zhejiang University
Effectively 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 adjoins the Ni-N3 centers in N-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.

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