Engineering Acid-Stable OER Electrocatalysts: Recent Advances in Main-Group Element Doping of Ir- and Ru-Based Oxides

As the world moves toward carbon neutrality, demand for highly efficient, durable oxygen evolution reaction (OER) electrocatalysts for proton exchange membrane water electrolysis (PEMWE) is increasing. Despite being benchmarks, IrO2 and RuO2 face a trade-off between activity and stability. Doping with main-group elements is an effective strategy for overcoming these challenges, as it leverages the simple electronic configurations and stable oxidation states of these elements to modulate the catalyst properties without introducing the complex redox behavior often associated with transition metal dopants. This review outlines four core enhancement mechanisms, electronic effects, lattice defects and strain, interfacial water restructuring, and morphology/crystallinity control, establishing a clear structure and property performance framework. It then categorizes recent advances in main-group-doped Ru/Ir oxides by the type of dopant used (alkali/alkaline-earth metals, group III–V metals, and nonmetallic elements), comparing synthetic approaches, physicochemical characterizations, and OER performance metrics. Finally, it highlights cutting-edge areas such as multicomponent/high-entropy doping, in situ characterization techniques, and machine learning-assisted high-throughput screening. It also stresses the need for standardized testing protocols and industrial scalability assessments. This review offers insights and design guidelines to develop high-performance, acid-stable, and stable OER catalysts for PEMWE commercialization.