Theoretical screening of 2D materials supported transition-metal single atoms as efficient electrocatalysts for hydrogen evolution reaction

Abstract The development of noble metal-free catalysts with high electrocatalytic activity to replace noble metal-based catalysts is essential innovation point of the future hydrogen evolution reaction (HER). In this work, we systematically investigate the electrocatalytic activity of single-atom catalysts (SACs) on two-dimensional (2D) substrate materials based on density functional theory (DFT). Through the phonon dispersion curves and ab initio molecular dynamics (AIMD) simulation calculations, the dynamic and thermal stability of BCN, B2O, C3N2 and CN monolayers are estimated. The catalytic activity of SACs in HER is described by the Gibbs free energy (ΔGH*) of hydrogen adsorption, without considering other processes involved in the HER. This descriptor is helpful for the rapid screening of efficient electrochemical hydrogen production catalysts. The results show that the catalytic performance of SACs in HER is closely related to the electronegativity of the active center site and its adjacent atoms. The ΔGH* of Ti@B2O, V@B2O, Sc@B2O, Mn@BCN, Sc@BCN, Cr@BCN, Sc@CN and Fe@C3N2 systems is close to 0 eV, and they have good stability and high reactivity, indicating that they are potential electrocatalysts for HER. Our findings contribute to the development of low cost noble metal-free catalysts and provide theoretical guidance for the design and screening of SACs on 2D substrate materials.