Fabrication of a core-shell structure platinum catalyst for the hydrogen evolution reaction: A new protocol by tailoring the reducibility of HxMoO3 template

Tailoring and optimizing Pt-based catalysts for the hydrogen evolution reaction (HER) is crucial for efficient energy conversion and storage. Reducing the amount of Pt used in HER catalysts is of paramount importance to enhance their application potential. It is highly challenging to precisely tailor Pt-based catalysts with the desired composition, uniform size, and homogeneous distribution, all while maintaining high catalytic activity and stability. Herein, the reducibility of HxMoO3 is meticulously controlled by the incorporated amount of H+ ions into MoO3, enabling the preparation of size-controllable Au nano-cores. Furthermore, a low-loading PtCo shell is constructed on the surface of the Au nano-cores to generate Au@PtCo core-shell heterostructures. The distinctive core-shell structure not only augments the utilization of the Pt atom but also facilitates the alteration of the electronic configuration in PtCo, thereby escalating the catalytic efficiency for HER. By utilizing the dual-active sites of PtCo shell, the overpotential is reduced to only 95 mV at a current density of 10 mA/cm2, accompanied by significant improvements in kinetics and enhanced stability. Furthermore, the presented method is universal and can be utilized to fabricate analogous Au@PtFe, Au@PtNi, and Au@PtCu catalysts.