Amorphous MoOX-Stabilized single platinum atoms with ultrahigh mass activity for acidic hydrogen evolution

Abstract It is highly desirable to develop Pt single-atom (SA) catalysts with an optimized mass activity for acidic hydrogen evolution reaction (HER), but it remains a significant challenge. In this study, a new Pt SA strongly coupled with amorphous MoOX (Pt-SA/ɑ-MoOx) is rationally designed. The synergistic effect between unsaturated Pt atoms and defective MoOx can significantly lower the reaction barrier contributing to the fast HER reaction kinetics. Hence, Pt-SA/ɑ-MoOx exhibits an ultrahigh mass activity of 52.0 A mgPt−1 at an overpotential of 50 mV, corresponding to better acidic HER activity than those reported previously for Pt SA-based catalysts. Furthermore, Pt-SA/ɑ-MoOx shows Pt-like kinetics with a small Tafel slope of 123 mV dec−1 and outstanding long-term electrochemical stability for 20 h. This developed synthetic method is also extended for the fabrication of other amorphous MoOx-supported SA catalysts (e.g. Ir, Au and Pb). As far as we know, our study reports the first example of the combination of metal SA and amorphous oxide for highly efficient electrocatalysis.