Anomalous Enhancement of the Electrocatalytic Hydrogen Evolution Reaction in AuPt Nanoclusters

TL;DR

This study demonstrates that AuPt nanoclusters on carbon nanotubes significantly enhance electrocatalytic hydrogen evolution, with atomistic machine learning revealing the atomic origin of this synergistic effect.

Contribution

The paper introduces ligand-free AuPt nanoclusters on carbon nanotubes for HER and uses machine learning to explain the atomic-scale synergy between Au and Pt.

Findings

Reduced overpotential for HER with AuPt nanoclusters

Surface Au atoms enhance Pt catalytic activity unexpectedly

Machine learning elucidates atomic origin of synergy

Abstract

Energy- and resource-efficient electrocatalytic water splitting is of paramount importance to enable sustainable hydrogen production. The best bulk catalyst for the hydrogen evolution reaction (HER), i.e., platinum, is one of the scarcest elements on Earth. The use of raw material for HER can be dramatically reduced by utilizing nanoclusters. In addition, nanoalloying can further improve the performance of these nanoclusters. In this paper, we present results for HER on nanometer-sized ligand-free AuPt nanoclusters grafted on carbon nanotubes. These results demonstrate excellent monodispersity and a significant reduction of the overpotential for the electrocatalytic HER. We utilize atomistic machine learning techniques to elucidate the atomic-scale origin of the synergistic effect between Pt and Au. We show that the presence of surface Au atoms, known to be poor HER catalysts, in a Pt(core)/AuPt(shell) nanocluster structure, drives an anomalous enhancement of the inherently high catalytic activity of Pt atoms.