Surface Van Hove Singularity Enabled Efficient Catalysis in Low-Dimensional Systems: CO Oxidation and Hydrogen Evolution Reactions

Surface Van Hove singularity (SVHS) triggers exciting physical phenomena distinct from the bulk. Herein, we explore the potential role of SVHS in catalysis for both CO oxidation and the hydrogen evolution reaction (HER) using the graphene/Ca2N (Gra/Ca2N) heterojunction and Pt2HgSe3 (001) surface as prototype systems. It is demonstrated that both systems with SVHS could serve as an electron bath to promote O-2 adsorption and subsequent CO oxidation with low energy barriers of 0.2-0.6 eV for the Gra/Ca2N and Pt2HgSe3 (001) surface and similarly facilitate the HER with near-zero hydrogen adsorption free energy. Importantly, the catalytically active sites associated with SVHS are well-defined and distributed over the whole surface plane, and further, the chemical reactivity of SVHS can also be tuned easily via adjusting its position with respect to E-F. Our study demonstrates the enabling power of SVHS and provides novel physical insights into the promising potential role of VHS in designing high-efficiency catalysts.

Automated summary

This study explores the potential role of Surface Van Hove singularity (SVHS) in CO oxidation and the hydrogen evolution reaction (HER). It is demonstrated that systems with SVHS can promote CO oxidation and HER, and their catalytically active sites are distributed over the whole surface plane.