Computational Design of BC ₃N ₂ Based Single Atom Catalyst for Dramatic Activation of Inert CO ₂ and CH ₄ Gases into CH ₃COOH with Ultralow CH ₄ 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-BC₃NM₂) 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, p_x, p_y, and p_z, in CO₂ reflects the existence of delocalized π bonds between C and O. This can interact with states of Pt(s), Pt(p_z), Pt(d_xz), Pt(d_yz), 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.

Keywords: 2D BC3N2 monolayer, CO2/CH4 capture and conversion, CH3COOH production, the first principles calculations