Proton conductive polyoxometalates

Abstract

Polyoxometalates (POMs), also known as transition metal‑oxygen clusters deliver unique physical and chemical properties such as low effective surface charge density, high thermal stability, and multi-electron acceptance, making them suitable for proton conductors. In recent years, proton conductive POMs have achieved significant progress in high performance (>10⁻² S/cm) comparable to conventional materials through structural regulation strategies. At the same time, the veiled conduction mechanism has been elucidated by structural analysis and characterization. In this review, the research of POMs (Keggin-type, Dawson-type, composite materials) in proton conduction is reviewed mainly from the design strategy, proton conductivity and mechanism, structure-function relationship, and application, finally with a detailed discussion of challenges and prospects. This review will provide more inspiration for exploring and applying proton-conducting POM materials.