Computational design of spatially confined triatomic catalysts for nitrogen reduction reaction

Book excerpt: The electrocatalytic process of nitrogen reduction reactions (NRR) offers a promising approach towards achieving sustainable ammonia production, acting as an environmentally friendly replacement for the conventional Haber-Bosch method. Density functional theory calculations have been utilized to design and investigate a set of catalysts known as triple-atom catalysts (TACs) for electrochemical NRR, which are supported on graphite-C3N3 nanosheets. Herein, we have systematically evaluated these TACs using stringent screening to assess their catalytic performance. Among the candidates, supported Pt3, Re3, and Ru3 trimers emerged as highly active with decent selectivity, involving a limiting potential range of -0.35~-0.11 V. According to analysis of electronic properties, we determined that high NRR activity stems from the d-π* electron-accepting and -donating mechanism. Significantly, the correlation between chemical activity of TACs and electronic structure was established as a pivotal physical parameter, which has led to the conclusion that we can precisely control the catalytic behavior of transition metal trimer clusters by selecting appropriate metal elements and designing moderate cluster-substrates interactions. In summary, these theoretical studies not only enhance our understanding of how catalytic properties are governed by metal-support interactions, regulating stability, activity, and selectivity, but also offer a useful method for screening and designing novel TACs for NRR.