Mesoporous Silica‐Stabilized Ceria Antioxidants for Enhancing PEMFC Durability

Enhancing the durability of polymer electrolyte membrane fuel cells (PEMFCs) is critical for advancing a hydrogen‐powered clean energy future. A major obstacle to improving PEMFC durability is reactive oxygen species (ROS) that deteriorate PEMFC performance by oxidizing membrane electrode assembly (MEA). While CeOx‐based nanomaterials are widely used as antioxidants, they often undergo decline in efficacy by their nanostructure deformation, hampering stable PEMFC operation. Here, mesoporous silica nanoparticles (MSNs) are reported as a stabilizer for antioxidants, effectively alleviating the CeOx disintegration. MSNs facilitate the formation of uniformly dispersed CeOx nanoparticles smaller than 2 nm having abundant oxygen vacancies and high proportion of Ce(III) oxidation states. The well‐defined mesoporous structure of MSNs effectively confines CeOx in the internal voids and prevents C…