Metastable-phase platinum oxide for clarifying the Pt–O active site for the hydrogen evolution reaction

Abstract

Platinum (Pt) catalyst is the core of current industrial catalysts and the holy grail for the hydrogen evolution reaction (HER). Previous studies have revealed that the HER activity of oxidized Pt is better than that of metal Pt⁰. Yet the relationship between the Pt–O structure and the catalytic activity has not been well explained to date. Herein, we report a new metastable platinum oxide, which achieved a low overpotential of 12 mV at a current density of −10 mA per square centimetre in acidic HER. DFT calculations showed that the [Pt–O] active site could be easily attacked by protons to form the Pt–H intermediate state during the HER and the adsorbed H could easily combine with any H atoms on adjacent O to form H₂.