Understanding Proton Exchange Membrane Water Electrolyzer Hydrogen Crossover Mitigation in Reactive Spray Deposition Technology Fabricated Dual Recombination Layers through Distribution of Relaxation Times Analysis

Abstract

Proton exchange membrane water electrolyzers (PEMWEs) are a promising technology to produce zero-carbon emission, renewable, high-purity hydrogen. [1] There is a need to reduce capital cost while improving performance for the progression of widespread development. The crossover of hydrogen from the cathode into the anode not only restricts cell performance, but also poses a safety hazard, as the crossover reaches the lower explosive limit of hydrogen in oxygen. [2] Previous work has been conducted on the fabrication and testing of Pt recombination layers in PEMWEs. The addition of the Pt recombination layer has proven to be an effective mitigation strategy for hydrogen crossover while improving performance. [3, 4] Further investigation is needed to understand the mechanisms of the Pt recombination layer.In this work, reactive spray deposition technology (RSDT) was used to deposit two Pt recombination layers separated by a membrane. Testing of a single cell 25 cm2 PEMWE was conducted. Polarization analysis, electrochemical impedance spectroscopy, and distribution of relaxation times were used to investigate the cell performance. Results show good cell performance and hydrogen crossover reduction, as well as insight to the mechanisms of the chemical reactions that occur on the dual recombination layer.