Work

Electronic Modulation via a Pd-CeO2 Heterointerface for Superior Alkaline Hydrogen Oxidation

Year: 2026

Type: article

Abstract: The sluggish kinetics of the hydrogen oxidation reaction (HOR) in alkaline media remain a primary bottleneck for anion exchange membrane fuel cells (AEMFCs), necessitating catalysts that synergistically optimize the adsorption of hydrogen (*H) and hydroxide (*OH) intermediates. Herein, we construct a well-defined heterointerface between Pd clusters and CeO2 on nitrogen-doped carbon (Pd-CeO2/NC) to electronically engineer the active sites. Spectroscopic studies and theoretical calculations collectively reveal that CeO2 acts as an electron acceptor, drawing electrons from Pd via interfacial Pd-O-Ce bridges. This charge transfer induces a downshift of the Pd d-band center, which optimally tunes the adsorption strength of both *H and *OH at the interface, thereby breaking the scaling relationship that limits HOR activity. The resulting Pd-CeO2/NC catalyst achieves an exceptional exchange current density of 3.66 mA cm−2, surpassing that of commercial Pt/C by a factor of two and ranking among the best reported noble metal catalysts. Furthermore, it exhibits outstanding long-term stability and remarkable CO tolerance, retaining high activity in an atmosphere containing 1000 ppm CO. This work underscores the profound efficacy of metal–oxide heterointerface engineering in regulating electronic structures for multi-intermediate optimization, offering a viable design principle for advanced alkaline HOR electrocatalysts.

Source: Molecules

DOI: 10.3390/molecules31081306