Transition Metal-Anchored Newly Synthesized Aza-Triphenylene Monolayer for Efficient Hydrogen Evolution Reaction: Insights from DFT

Overview & Synopsis

First-principles calculations were employed to explore the hydrogen evolution reaction (HER) activity in two-dimensional aza-triphenylene monolayers functionalized with transition metals. Among the various metals studied, Co, Ru, and Y demonstrate outstanding catalytic efficacy, lowering the hydrogen adsorption free energy from -0.78 eV for pure aza-triphenylene to 0.05, 0.20, and 0.06 eV, respectively. Volcano plot analysis corroborates their enhanced HER activity. Ab initio molecular dynamics simulations confirm thermal stability, while the electronic structure and charge transfer analysis reveal the strong catalyst-surface interaction. Metal decoration also improves the carrier mobility, particularly for Ru-functionalized aza-triphenylene. The climbing-image nudged elastic band calculations for Co-functionalized aza-triphenylene exhibit activation barriers of 1.61, 2.29, and 5.88 eV for the Volmer, Heyrovsky, and Tafel reactions, respectively, highlighting a preferred Volmer-Heyrovsky route with the Heyrovsky being the rate-determining step. These findings highlight the potential of transition-metal-functionalized aza-triphenylene as a promising platform for developing efficient HER electrocatalysts.