Adsorption Energetics of Atoms and Diatomic Gases with Electrocatalysis Approach towards Hydrogen and Oxygen Evolution Reaction on Pt Surfaces

Abstract

The computational study of chemisorption of atoms and gases intends to provide a great insight in the developing of an up‐to‐date elusive assessment of a correct choice of the site for the adsorption on platinum surfaces i. e. a key step for many chemical processes in catalysis and surface sciences. A density functional theory (DFT) calculation using generalized gradient approximation (GGA) scheme and supercell model with the inclusion of modified dispersion correction (DFT−D2) has been performed to explore the adsorption trends and evaluate adsorption energies of H, C, N, O, and S (atoms) and H2, C2, N2, O2, and S2 (homonuclear diatomic molecules) on Pt(111) and Pt(100) surfaces for multiple sites, in search of the most active catalytic site. Our chemisorption data revealed that the incorporation of DFT−D2 correction strengthens the adsorption energy by the amount of 0.05 eV to 0.67 eV for atoms and gases. Finally, this study focuses on unveiling catalytic activity of the two seemingly simplest electrochemical reactions; the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) on numerous sites of Pt surfaces using the adsorption strength of H and O with the inclusion of DFT−D2 correction, which shows the good consistency with the results of standard DFT calculations. The highest catalytic activity towards HER is shown by Pt(100) in contrast to the best OER catalytic activity by Pt(111) surface with their respective most favorable 4fh and top sites.

Theoretical Investigation of HER and OER Electrocatalysts Based on the 2D R-graphyne Completely Composed of Anti-Aromatic Carbon Rings

“…In previous reports, some HER or OER electrocatalysts have been designed and developed [4][5][6][7][8][9]. So far, the benchmark electrocatalysts for HER and OER are Pt [10] and IrO 2 /RuO 2 [11,12], respectively. However, the scarcity and high cost of these precious metals have greatly hindered their large-scale applications.…”