Synergistic coupling of Pt nanoparticles with LaPO4 proton reservoirs and MoB2 electron conductors for highly efficient hydrogen evolution

Developing efficient electrocatalysts for the hydrogen evolution reaction (HER) is essential for sustainable energy conversion. In this work, a ternary Pt/LaPO 4 /MoB 2 heterostructure has been synthesized using a combined sol-gel, solid-state reaction and impregnation method. The optimal 1.5 wt% Pt/LaPO 4 /MoB 2 catalyst exhibits remarkable HER activity with an low overpotential of 84 mV at 10 mA cm −2 , and surpasses the commercial Pt/C at high current density (>100 mA cm −2 ). This enhanced HER performance is originated from a unique synergistic effect where metallic MoB 2 facilitates rapid electron transfer while LaPO 4 acts as a proton reservoir by forming [HPO 4 ] 2- structures to increase local H + concentration. This robust interfacial coupling effectively optimizes the electronic structure and accelerates charge-carrier transfer kinetics via the triple-phase boundaries, offering a promising strategy for large scale and high efficiency hydrogen production.