Understanding the Impact of Conditioning Protocols for Water Electrolyzers on Durability

Abstract

The global push towards climate neutrality has intensified research efforts on green hydrogen production technologies. Among them, proton exchange water electrolysis (PEMWE) stands out as a highly efficient technology for producing green hydrogen using renewable energies. Nevertheless, a significant reduction in the cost of PEMWE while maintaining its durability over its operational periods is imperative. The DOE’s Hydrogen Earthshot target aims to achieve $1 per 1kg of H2 production within the decade. Reducing the amount of expensive iridium catalysts also reduces the durability of PEMWE. Hence, understanding the degradation mechanisms of low Ir loading PEMWE holds utmost importance. One key step in the evaluation of PEMWE is the break-in or conditioning step. Ensuring optimal conditioning is crucial to guarantee the peak performance of membrane electrode assembly (MEA) before assessing the durability of the catalyst thereby ensuring representative and reproducible results.This research aims to comprehensively evaluate various conditioning protocols for PEMWE and their impact on durability. Utilizing a combination of electrochemical, electron, and X-ray characterization techniques. Accelerated stress tests (AST) will be conducted after each conditioning protocol to evaluate the degradation rate of the catalyst. Ex-situ characterization of the MEA post-conditioning as well as post-AST offers a comprehensive understanding of how the catalyst’s initial state, such as the iridium oxidation state, following the conditioning step directly influences the durability. The goal is to develop an optimal conditioning protocol for PEMWE, that considers the performance and durability challenges associated with low catalyst loading. Acknowledgment This research is supported by the U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office through the Hydrogen from Next-generation Electrolyzers of Water (H2NEW) consortium with support from Dave Peterson and McKenzie Hubert.