NO oxidation with H₂O₂ as the oxidant is a promising green denitration technology. However, the current metal oxide catalysts still have many disadvantages for this reaction, such as insufficient catalytic activity for H₂O₂ activation, poor selectivity, and low stability. In this study, we employ atomically dispersed Co anchored on SBA-15 with Co-O₄ structure for NO oxidation, which achieves a 90% removal efficiency of NO under low molar ratio of H₂O₂ to NO (1.56), ultra-low temperature (80 °C), and ultra-high space velocity (720,000 h^–1), representing the top-level performance among previously reported catalysts. More interestingly, our work reveals that by taking advantage of the uniform Co-O₄ structure, H₂O₂ is mainly directionally converted into ·O₂^– at the Co-O₄ site, and ·O₂^– plays a key role for achieving the deep-oxidation of NO to produce NO₃^–, which is contrast to the previously reports that ¹O₂ is the main free radical for NO oxidation. This study highlights the great potentials of single-atom catalysts for improving the H₂O₂ utilization performance for NO oxidation.

Electrochemical carbon dioxide reduction reaction (CO₂RR) into high-value added chemicals and fuels has aroused wide attention, but suffers from high overpotential and poor selectivity. Herein, nitrogen-doped carbon supported Fe and Mn heteronuclear single atom catalysts with different Fe and Mn inter-site distance were fabricated via a templating isolation approach and tested for CO₂RR to CO in an aqueous solution. The catalyst with atomically dispersed Fe and Mn sites in close proximity exhibited the highest CO₂RR performance, with a CO Faradaic efficiency of 96% at a low overpotential of 320 mV, and a Tafel slope of only 62 mV·dec⁻¹, comparable to state-of-the-art gold catalysts. Experimental analysis combined with theory highlighted that single Mn atom at the neighboring site of Fe enhanced the electronic localization of Fe center, which facilitated the generation of key *COOH intermediate as well as CO* desorption on Fe, leading to superior CO₂RR performance at low overpotentials. This work offers atomic-level insights into the correlation between the inter-site distance of atomic sites and CO₂RR performance, and paves a new avenue for precise control of single-atom sites on carbon surface for highly active and selective electrocatalysts.