Single transition metal anchored C9N4 sheets as an efficient catalyst for CO oxidation: a first-principles study

Abstract

Single-atom catalysts (SACs) often exhibit superb catalytic activity due to their high atom utilization. By comparing the adsorption energies of O₂ and CO adsorbed on TM@C₉N₄, we expect that Co and Ni anchored at the cavity of C₉N₄ exhibit a higher catalytic activity for CO oxidation. For the entire reaction, the Eley–Rideal, New Eley–Rideal, Ter-molecular Eley–Rideal and Langmuir–Hinshelwood mechanisms are all taken into account. Depending on the reaction mechanisms, the catalysts Co@C₉N₄ and Ni@C₉N₄ show excellent activity, with a kinetic energy barrier ranging from 0.19 eV to 0.54 eV for the former, while the corresponding energy barrier is 0.26 eV to 0.44 eV for the latter. The superior stability and activity of Co/Ni@C₉N₄ can efficiently oxidize the large amounts of CO caused by inadequate combustion of coal and natural gas resources.