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Among the alkaline earth-based perovskite oxides, the Ba-based perovskites have superior chemical stability and tunable electrical/catalytic property via chemical substitution/doping. One of the best-known examples is Ba3Ca1.18Nb1.82O8.73 as ceramic proton...

The use of thinner membranes in polymer electrolyte water electrolysis increases the likelihood of forming an explosive H2/O2 mixture in the anode stream. Doping Pt nanoparticles into a Nafion membrane as recombination catalyst effectively lowers the hydrogen crossover. Here, we propose the additional co-doping of cerium-zirconium oxide as radical scavenger to mitigate membrane degradation. Our results show over 4-fold reduction of anodic hydrogen content compared to a non-doped membrane, and a nearly 3-fold decrease of fluoride release rate compared to the membrane with only Pt-doping at 80°C and differential pressure (pc = 3 bar, pa = 1 bar) operation.

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Polymer electrolyte water electrolysis (PEWE) is one of the key technologies for green hydrogen production. It has the advantages of operating at relatively high current densities and differential pressures. The hydrogen gas produced, under high cathodic pressure and with a thin membrane, tends to cross over to the anode chamber, forming explosive H2/O2 gas mixture and posing severe safety concerns for the device. Literature has shown that one effective solution is the use of Pt as the recombination catalyst. On the other hand, radical attacks to the PFSA-based membrane leads to possible thinning and pinhole formation, which deteriorates the electrochemical performance and eventually causes cell failure. To this end, ceria is often employed as a radical scavenger. In this work, we report the co-incorporation of Pt and cerium-zirconium oxide in solution-cast Nafion membranes for the dual functions of suppressing hydrogen crossover and scavenging of radicals. We show that the hydrogen in oxygen content in the anode gas stream is significantly reduced with the incorporation of Pt, and the inclusion of cerium-zirconium oxide inside the membrane is able to decrease fluoride release rate in a 100-hour constant-current water electrolysis measurement. This study provides guidance in developing proton exchange membranes with enhanced durability and safe operating range.