Theory assisted design of N-doped tin oxides for enhanced electrochemical CO₂ activation and reduction

Clearly understanding the structure-function relationship and rational design of efficient CO₂ electrocatalysts are still the challenges. This article describes the molecular origin of high selectivity of formic acid on N-doped SnO₂ nanoparticles, which obtained via thermal treatment of g-C₃N₄ and SnCl₂·2H₂O precursor. Combined with density functional theory (DFT) calculations, we discover that N-doping effectively introduces oxygen vacancies and increases the charge density of Sn sites, which plays a positive role in CO₂ activation. In addition, N-doping further regulates the adsorption energy of *OCHO, *COOH, *H and promotes HCOOH generation. Benefited from above modulation, the obtained N-doped SnO₂ catalysts with oxygen vacancies (Ov-N-SnO₂) exhibit faradaic efficiency of 93% for C₁ formation, 88% for HCOOH production and well-suppression of H₂ evolution over a wide range of potentials.