@article{Zhang2025, 
author = {Junxi Zhang and Xin Cai and Xin Li and Chunjian Zhang and Sanhuang Ke and Cunman Zhang and Yuen Wu and Rui Lin},
title = {Low loading of lrO2/TiO2 enabled by Pd promoter in acidic water electrolysis},
year = {2025},
journal = {Nano Research},
volume = {18},
number = {12},
pages = {94908065},
keywords = {water splitting, low-iridium, palladium doping, Ir local environment, reaction pathway},
url = {https://www.sciopen.com/article/10.26599/NR.2025.94908065},
doi = {10.26599/NR.2025.94908065},
abstract = {Reducing iridium (Ir) loading in proton exchange membrane water electrolyzers (PEMWEs) while maintaining high catalytic performance remains a critical challenge. Herein, we develop a palladium (Pd) doped IrO2/TiO2 catalyst with a high mass activity of 750.4 A·gIr−1 at 1.53 V during acidic oxygen evolution reaction (OER). When integrated into a PEMWE as anode catalyst, it delivers a high current density of 3.6 A·cm−2 at 1.9 V even with Ir loading as low as 0.35 mgIr·cm−2, which surpasses the DOE 2025 target (3 A·cm−2@1.9 V). Systematic characterizations reveal that Pd doping induces a low Ir coordination environment, leading to the formation of abundant Ir(III) species and providing more active sites. It promotes the OER kinetics by weakening the adsorption behavior of *OH intermediate, which is further confirmed by the downshift of Ir d-band center through First-principles calculations. The reduced Ir–O bonds interaction facilitates the adsorbate evolution mechanism (AEM) pathway, with a much lower kinetics energy barrier compared to the undoped one, thereby balancing good activity and stability during the OER process. This work offers a strategy for designing low-Ir electrocatalysts for high-performance PEMWEs.}
}