Breaking the activity-stability trade-off of platinum-based catalysts in anion exchange membrane water electrolysis via robust Pt-O-Ce interfacial bonding

Construct PtCu/CeO 2 heterojunction to resolve alkaline HER activity-stability trade-off dilemma. • Form strong Pt-O-Ce interfacial bonds to restrain Pt oxidation and metal leaching. • CeO 2 serves as efficient promoter to drastically accelerate water dissociation step of alkaline HER. • Assembled AEMWE cell delivers 2500 h ultra-long stability at industrial current density. The persistent activity-stability trade-off in electrocatalysts, driven by the dynamic evolution of active sites, severely limits the practical application of anion exchange membrane water electrolysis (AEMWE). Herein, we construct a robust PtCu/CeO 2 heterostructure that simultaneously achieves superior activity and long-term durability for alkaline hydrogen evolution reaction (HER). The catalyst exhibits an ultralow overpotential of 10 mV at 10 mA cm −2 and a small Tafel slope of 23.2 mV dec −1 , significantly outperforming conventional Pt/Ni(OH) 2 and Pt/C electrodes. In a full AEMWE cell, the PtCu/CeO 2 ||NiFe LDH system requires only 1.71 V to reach 1 A cm −2 and maintains stable operation for 2500 h with negligible decay, ranking it among the best-performing alkaline HER catalysts. Mechanistically, Cu alloying optimizes the hydrogen adsorption energy of Pt, while CeO 2 acts as an effective water dissociation promoter to accelerate the overall reaction kinetics. Moreover, strong Pt-O-Ce interfacial bonding between the thermodynamically stable CeO 2 and PtCu alloy, together with significant hybridization of Pt 5d/Cu 3d and Ce 4 f/O 2p orbitals, effectively suppresses the dissolution and oxidation of Pt sites. thereby enhancing the durability of the catalyst under high-current-density operation. This work offers a viable strategy to overcome the activity-stability dilemma in HER catalysts for industrial AEMWE. Download: Download high-res image (142KB) Download: Download full-size image This work presents a robust PtCu/CeO 2 heterostructure that breaks the activity-stability trade-off in alkaline HER for AEMWE. CeO 2 acts as an efficient water dissociation promoter, accelerating the Volmer step. It also serves as a thermodynamically stable scaffold. Strong Pt-O-Ce interfacial bonding optimizes the electronic structure and suppresses Pt dissolution and oxidation. This catalyst achieves superior activity with an overpotential of 10 mV at 10 mA cm −2 . In a full AEMWE cell, it demonstrates stable operation for 2500 h at 1 A cm −2 .