The alkaline hydrogen evolution reaction (HER) is kinetically hindered by the sluggish dissociation of water, while the high cost and limited utilization efficiency of Pt further restrict its practical application. In contrast, oxophilic transition metals such as Ni and Co can facilitate water adsorption and dissociation; therefore, constructing cooperative active sites between Pt and transition metals provides a promising strategy to simultaneously promote water activation and hydrogen-intermediate (H^*) conversion. Meanwhile, porous carbon supports can improve the dispersion and stability of metal nanoparticles and facilitate interfacial mass transport. Herein, coal-derived porous carbon was employed as a support for a low-Pt PtNiCo ternary alloy to improve alkaline HER activity, Pt utilization efficiency, and long-term stability. Coal powder was mixed with KOH at a mass ratio of 1:3 and ground for 30 min, followed by heating to 800 °C at 5 °C min^-1 under N₂ and holding for 2 h. After acid washing with 1.0 M HCl for 6 h, coal-derived porous carbon (BPC) was obtained. Subsequently, 0.10 g BPC, 0.0314 g Ni(NO₃)₂·6H₂O, 0.0313 g Co(NO₃)₂·6H₂O, and 0.010 g polyvinylpyrrolidone were dispersed in 1.0 mL deionized water, ultrasonicated for 30 min, freeze-dried for 24 h, and annealed at 800 °C for 2 h under N₂ to obtain NiCo/BPC. Then, 36 mg NiCo/BPC was dispersed in 10 mL deionized water with 20 μL of 0.643 mol L^-1 H₂PtCl₆ and reduced with 50 mL of 0.1 mol L^-1 NaBH₄ to obtain PtNiCo/BPC. Pt/BPC, NiCo/BPC, and commercial Pt/C served as references; structural characterization, electrochemical measurements, and DFT calculations were used to elucidate the structure-performance relationship. KOH activation produced a hierarchical micro/mesoporous framework that stabilized well-dispersed PtNiCo nanoparticles averaging 4.8 nm. In 1.0 M KOH, PtNiCo/BPC required an overpotential of only 17.0 mV to achieve 10 mA cm^-2 and delivered a Pt mass activity of 1342.12 mA mgPt^-1 at an overpotential of 100 mV, approximately 4.05 times that of commercial Pt/C. After 180 h at 250 mA cm^-2, the potential shifted by only approximately 11 mV, demonstrating high HER activity, efficient Pt utilization, and excellent durability. XPS measurements and DFT calculations revealed that Pt incorporation induced directional charge transfer from NiCo toward Pt and decreased the H₂O dissociation barrier from 1.22 to 1.06 eV. Reaction-path analysis further showed that Co sites preferentially promote H₂O adsorption and O-H bond cleavage, whereas the generated H^* migrates to adjacent Pt sites for conversion and H₂ formation, establishing a dual-site mechanism in which Co facilitates water dissociation and Pt promotes H^* conversion. Together, the hierarchical BPC support and PtNiCo interfacial/multisite synergy enhance alkaline HER kinetics and Pt utilization, enabling efficient and stable hydrogen evolution with reduced Pt usage and offering a route toward low-Pt electrocatalysts and high-value utilization of coal-derived carbon materials.
 

coal-derived porous carbon; PtNiCo alloy; alkaline hydrogen evolution; dual-site synergy; low-Pt electrocatalyst

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