Single-atom Anchored Curved Carbon Surface for Efficient CO2 Electro-reduction with Nearly 100% Co Selectivity And Industrially-relevant Current Density.

Abstract

Although single metal atoms on porous carbons (PCs) have been widely used in electrochemical CO2 reduction reaction, these systems have long relied on flat graphene-based models, which are far beyond reality because of abundant curved structures in PCs, the effect of curved surface has long been ignored. In addition, the selectivity generally decreases under high current density, which severely limits practical application. Herein, the theoretical calculations reveal that the single-Ni-atom on curved surface can simultaneously enhance the total density of states around Fermi level and decrease the energy barrier for *COOH formation, thereby enhancing catalytic activity. We report a rational molten salt approach for preparing PCs with ultra-high specific surface area of up to 2635 m2 g-1 . As determined by cutting-edge techniques, single-Ni-atom on curved carbon surface is obtained and used as catalysts for electrochemical CO2 reduction. The CO selectivity reaches up to 99.8% under industrial-level current density of 400mA cm-2 , outperforming state-of-the-art PC-based catalysts. Not only this work offers a new method for the rational synthesis of single atom catalysts with strained geometry to host rich active sites, but also provides in-depth insights for the origin of catalytic activity of curved structure-enriched PC-based catalysts. This article is protected by copyright. All rights reserved.