Platinum single-atom and cluster catalysis of the hydrogen evolution reaction

TLDR

Platinum-based catalysts are the most effective electrocatalysts for hydrogen evolution, yet their efficiency is limited because only surface atoms are active. The study aims to maximize platinum utilization by downsizing nanoparticles to single atoms. The authors synthesize isolated single platinum atoms and small clusters on nitrogen‑doped graphene via atomic layer deposition. These single‑atom catalysts show up to 37‑fold higher activity and superior stability than commercial Pt/C, attributed to partially unoccupied Pt 5d states on the support.

Abstract

Platinum-based catalysts have been considered the most effective electrocatalysts for the hydrogen evolution reaction in water splitting. However, platinum utilization in these electrocatalysts is extremely low, as the active sites are only located on the surface of the catalyst particles. Downsizing catalyst nanoparticles to single atoms is highly desirable to maximize their efficiency by utilizing nearly all platinum atoms. Here we report on a practical synthesis method to produce isolated single platinum atoms and clusters using the atomic layer deposition technique. The single platinum atom catalysts are investigated for the hydrogen evolution reaction, where they exhibit significantly enhanced catalytic activity (up to 37 times) and high stability in comparison with the state-of-the-art commercial platinum/carbon catalysts. The X-ray absorption fine structure and density functional theory analyses indicate that the partially unoccupied density of states of the platinum atoms' 5d orbitals on the nitrogen-doped graphene are responsible for the excellent performance.