Multi-atomic loaded CN catalysts for CO reduction to CO or formic acid.

In recent years, the development of highly active and selective electrocatalysts for the electrochemical reduction of CO to produce CO and formic acid has aroused great interest, and can reduce environmental pollution and greenhouse gas emissions. Due to the high utilization of atoms, atom-dispersed catalysts are widely used in CO reduction reactions (CORRs). Compared with single-atom catalysts (SACs), multi-atom catalysts have more flexible active sites, unique electronic structures and synergistic interatomic interactions, which have great potential in improving the catalytic performance. In this study, we established a single-layer nitrogen-graphene-supported transition metal catalyst (TM-CN) based on density functional theory, facilitating the reduction of CO to CO or HCOOH with single-atom and multi-atomic catalysts. For the first time, the TM-CN monolayer was systematically screened for its catalytic activity with molecular dynamics, density of states, and charge density, confirming the stability of the TM-CN catalyst structure. Furthermore, the Gibbs free energy and electronic structure analysis of 3TM-CN revealed excellent catalytic performance for CO and HCOOH in the CORR with a lower limiting potential. Importantly, this work highlights the moderate adsorption energy of the intermediate on 3TM-CN. It is particularly noteworthy that 3Mo-CN exhibited the best catalytic performance for CO, with a limiting potential () of -0.62 V, while 3Ti-CN showed the best performance for HCOOH, with a corresponding of -0.18 V. Additionally, 3TM-CN significantly inhibited competitive hydrogen evolution reactions. We emphasize the crucial role of the d-band center in determining products, as well as the activity and selectivity of triple-atom catalysts in the CORR. This theoretical research not only advances our understanding of multi-atomic catalysts, but also offers new avenues for promoting sustainable CO conversion.