A Universal Principle to Accurately Synthesize Atomically Dispersed Metal–N(4) Sites for CO(2) Electroreduction

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%. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40820-020-00443-z) contains supplementary material, which is available to authorized users.