Self-Assembly-Cooperating in Situ Construction of MXene–CeO2 as Hybrid Membrane Coating for Durable and High-Performance Proton Exchange Membrane Fuel Cell

The chemical durability of the membrane is a central issue in the development of proton exchange membrane fuel cells (PEMFCs), while incorporating cerium oxide as a free radical scavenger is one effective strategy to enhance durability. However, simultaneous dispersion and anchoring of cerium oxide in PEM have rarely been reported. Herein, MXene–CeO2 hybrids are prepared by self-assembly-cooperating in situ nucleation growth routes, then the MXene–CeO2 is sprayed on the cathode side of the r-PEM to fabricate a hybrid membrane with free radical resistance. The in situ nucleation growth of CeO2 on MXene nanosheets carriers effectively inhibits agglomeration and induces an anchoring effect through their interaction forces, forming CeO2 nanoparticles with a high specific surface and stable attachment, maximizing the free radical scavenging impact at the forefront of the membrane. The hybrid membrane with a loading of 0.1 mg cm–2 MXene–CeO2 exhibits a lower OCV decay rate (0.53 mV h–1), thickness variation (2.8%), and hydrogen crossover (2.6 mA cm–2) and higher maximum power density (1222.5 mW cm–2) than pristine r-PEM after accelerated degradation testing for 150 h.