A Universal Principle to Accurately Synthesize Atomically Dispersed Metal–N4 Sites for CO2 Electroreduction
Wanzhen Zheng, Feng Chen, Qi Zeng, Zhongjian Li, Bin Yang, Lecheng Lei, Qinghua Zhang, Feng He, Xi‐Lin Wu, Yang Hou
Abstract
Abstract Atomically dispersed metal–nitrogen sites-anchored carbon materials have been developed as effective catalysts for CO 2 electroreduction (CO 2 ER), but they still suffer from the imprecisely control of type and coordination number of N atoms bonded with central metal. Herein, we develop a family of single metal atom bonded by N atoms anchored on carbons (SAs–M–N–C, M = Fe, Co, Ni, Cu) for CO 2 ER, which composed of accurate pyrrole-type M–N 4 structures with isolated metal atom coordinated by four pyrrolic N atoms. Benefitting from atomically coordinated environment and specific selectivity of M–N 4 centers, SAs–Ni–N–C exhibits superior CO 2 ER performance with onset potential of − 0.3 V, CO Faradaic efficiency (F.E.) of 98.5% at − 0.7 V, along with low Tafel slope of 115 mV dec −1 and superior stability of 50 h, exceeding all the previously reported M–N–C electrocatalysts for CO 2 -to-CO conversion. Experimental results manifest that the different intrinsic activities of M–N 4 structures in SAs–M–N–C result in the corresponding sequence of Ni > Fe > Cu > Co for CO 2 ER performance. An integrated Zn–CO 2 battery with Zn foil and SAs–Ni–N–C is constructed to simultaneously achieve CO 2 -to-CO conversion and electric energy output, which delivers a peak power density of 1.4 mW cm −2 and maximum CO F.E. of 93.3%.