Enhancing neutral hydrogen production by disrupting the rigid hydrogen bond network on Ru nanoclusters through Nb2O5-mediated water reorientation

Abstract

The hydrogen evolution reaction (HER) under neutral conditions is highly important for achieving practical hydrogen production. However, catalysts often exhibit lower activity under neutral conditions, the cause of which remains an unsolved puzzle. By employing ab initio molecular dynamics and in situ surface-enhanced Raman spectroscopy, we investigated the regulatory role of Nb₂O₅ on interfacial water molecules, which determines the activity of neutral HER. The rigid interfacial water layer in a neutral medium inhibits the transport of intermediates (H₂O*/OH*) at the interface between Ru nanoclusters and the electrolyte. However, electron-rich Nb₂O₅ can overcome this challenge by altering the orientation of H₂O molecules to disrupt the H-bond network, thereby increasing the availability of H₂O on the surface of catalyst. Finally, Ru/Nb₂O₅ exhibited excellent activity, even surpassing that of commercial Pt/C catalysts at higher current density. This study provides new avenues for constructing coupled catalysts to activate interfacial water and enhance neutral HER.