Pore-Size Effect of Pt Incorporation in MOF-Derived PtNi/C Catalysts for Hydrogen Evolution

The hydrogen evolution reaction (HER) is a critical step in water electrolysis, holding significant potential for converting intermittent renewable energy into a storable hydrogen fuel. In this work, we synthesized two types of bimetallic PtNi nanoparticles (NPs) embedded in porous metal-organic framework (MOF)-derived carbon nanomaterials, designated as L-PtNi-C and S-PtNi-NC, respectively. In this case, PtCl₄^2- complex ions cannot be effectively entered into the narrow pores of Ni-ABDC (pore size: 4.63 and 6.80 Å), and its derived S-PtNi-NC shows inferior HER. In contrast, benefiting from its large-pore structure and adjustable chemical composition, the obtained L-PtNi-C from NiOF-1 (channel diameter: 15.3 Å) demonstrates exceptional performance as an efficient HER electrocatalyst. Specifically, it exhibits low overpotentials of 38 and 39 mV at -10 mA cm^-2 in both acidic and alkaline media, respectively, along with stability exceeding 50 h. The synergistic alloying of Pt and Ni not only enhances catalytic efficiency but also reduces Pt consumption, thereby improving the overall economic feasibility of the catalyst. These findings highlight the potential of MOF-derived low-loading noble metal-based carbon nanomaterials as highly efficient and stable HER electrocatalysts.