First-principles Density Functional Theory Elucidation of the Hydrogen Evolution Reaction on TM-promoted TiC2 (TM=Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au)

Abstract

Single-atom-catalyst-based systems have been attractive by virtue of their desirable catalytic performance. Herein, the possibility of the 15 transition-metal (TM)-promoted (TM=Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Cd, Os, Ir, Pt, Au, and Hg) and their hydrogen evolution reaction (HER) performance were investigated on two-dimensional titanium carbides (TiC2). It is found that the adsorption strength of TMs on TiC2 is stronger than that of TMs on gamma-graphyne and weaker than that of TMs on Ti3C2. Among the fifteen investigated catalysts, Ru-TiC2, Ag-TiC2, Ir-TiC2, Au-TiC2, and Fe-TiC2 exhibits overpotential of -0.18, -0.15, -0.18, -0.17, and -0.04 V, respectively. In addition, the Volmer-Tafel step was preferred to the Volmer-Heyrovsky step on Fe-TiC2. This work suggests that Fe-TiC2 is possibly a superior HER electrocatalyst.