酸性電解質における電気化学的水素発生を強化するパラジウム導電性金属有機構造体相互作用

Strong metal-metal-organic framework (MOF) interactions can markedly enhance electrocatalytic hydrogen evolution, yet the intrinsically poor conductivity of most MOFs constrains their performance. Here, we employ a conductive 2,3,6,7,10,11-hexaaminotriphenylene (HITP)-based MOF to anchor sub-5 nm Pd nanoparticles (<1.1 wt.%). The metal-node- and ligand-dependent interfacial interaction between Pd and M-HITP (M = Fe, Ni, Cu, Zn) endows Pd/M-HITP with markedly higher intrinsic activity than the pristine MOFs. Among the resulting hybrids, Pd/Fe-HITP exhibits outstanding activity, requiring only 15 mV to reach -10 mA cm^{- 2} and maintaining stability for over 100 h. Morphology modulation to Fe-HITP nanosheets further reduces overpotentials to 9 and 74 mV at -10 and -100 mA cm^{- 2}, respectively, by mitigating mass transport limitations. Density functional theory calculations reveal that Fe sites, rather than Pd, serve as the true active centers, with the Pd-Fe-HITP interaction upshifting the Fe d-band center, enhancing *H adsorption, and lowering the free energy barrier to 0.044 eV. This work highlights conductive MOFs as promising platforms for interfacial design in advanced electrocatalysts.