Computational design of BC3N2 based single atom catalyst for dramatic activation of inert CO2 and CH4 gasses into CH3COOH with ultralow CH4 dissociation barrier

Abstract

The production of CH3COOH from CO2 and CH4 has stimulated much interest due to the high energy density of C2 species. Various kinds of catalysts have been developed while the high dissociation barrier of CH4 and low selectivity still hinders the efficiency of the reaction. We have herein proposed a novel catalyst with single metals loaded on 2D BC3N2 substrate (M@2D-BC3N2) based on density functional theory. Among numerous candidates, Pt@2D-BC3N2 possesses the most favorable reactivity with an ultralow barrier of CH4 splitting (0.26 eV), which is due to the efficient capture ability of CH4 on Pt site. Besides, the selectivity for CH3COOH is also very high, which mainly stems from the unique electronic properties of molecules and substrate: The degenerated states, including s, px, py and pz, in CO2 reflects the existence of delocalized π bonds between C and O. This can interact with states of Pt(s), Pt(pz), Pt(dxz), Pt(dyz),and Pt(z2) in Pt@2D-BC3N2. The kinetics model also proves that our system can promote CH3COOH production via simply increasing the temperature or the coverage of CH4 and CO2. Our results provide a reasonable illustration in clarifying mechanism and propose promising candidates with high reactivity for further study.