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) are 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 surfaces has long been ignored. In addition, the selectivity generally decreases under high current density, which severely limits practical application. Herein, theoretical calculations reveal that a single-Ni-atom on a 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. This work reports 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, a single Ni atom on a curved carbon surface is obtained and used as a catalyst for electrochemical CO₂ reduction. The CO selectivity reaches up to 99.8% under industrial-level current density of 400 mA cm^-2 , outperforming state-of-the-art PC-based catalysts. This work not only 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.