Non-precious metal single-atom loading and further strain engineering on SrTiO3 (100) surface for optimizing hydrogen evolution reaction

Single-atom loading of the non-precious transition metals (M = Ti, V, Mn, and Fe) on the (100) surface of SrTiO3 (STO) was theoretically investigated to evaluate the hydrogen evolution reaction (HER) with Gibbs free energy for hydrogen adsorption (Delta GH* ). V1-STO stood out owing to the Delta GH* of - 0.08 eV, which was competitive to the metallic Pt with the value of - 0.09 eV. The d band center rationalized well the primary screening of single-atom non-precious transition metals on STO. Furthermore, strain engineering was applied to refine the HER performance of V1-STO. The tensile strain increased the Delta GH*, while the compressed strain decreased the Delta GH* . A new descriptor of the d orbital splitting (epsilon d-gap) was proposed to explain the optimization of the HER performance arising from the surface strains. This work conceives a combinational strategy to evaluate the HER performance, and may give guidance for the sequential design of HER catalysts.

Automated summary

The single-atom loading of non-precious transition metals (M = Ti, V, Mn, and Fe) on the (100) surface of SrTiO3 (STO) was theoretically studied to assess the hydrogen evolution reaction (HER) with the Gibbs free energy for hydrogen adsorption (Delta GH*). V1-STO showed a competitive Delta GH* value of -0.08 eV, comparable to metallic Pt (-0.09 eV). The d band center explained the primary screening of single-atom non-precious transition metals on STO. Furthermore, strain engineering was utilized to enhance the HER performance of V1-STO. Tensile strain increased Delta GH*, while compressed strain decreased Delta GH*. A new descriptor of the d orbital splitting (epsilon d-gap) was proposed to elucidate the optimization of HER performance due to surface strains. This work introduces a combined strategy to evaluate HER performance and offers guidance for the sequential design of HER catalysts.