A Guide to Electrocatalyst Stability Using Lab-Scale Alkaline Water Electrolyzers
Authors: Marquez Raul A. , Espinosa Michael , Kalokowski Emma , Son Yoon Jun , Kawashima Kenta , Le Thuy Vy , Chukwuneke Chikaodili E. , Mullins Charles Buddie 
Published: August 2024

Green hydrogen from low-temperature water electrolysis has received significant attention with a projected thousand-fold global capacity expansion by 2030.1 Electrocatalyst research is crucial for water electrolysis technologies and has garnered substantial attention. However, despite a surge in publications centered on promising electrocatalytic materials, often claiming "outstanding" performance, few studies have scaled these materials to more realistic setups. This gap primarily stems from the inadequacy of testing environments and operating conditions in academic research. The prevalent use of three-electrode cell configurations fails to mimic practical electrolyzer conditions accurately.2,3 Electrocatalytic performance in these setups does not effectively represent real electrolysis devices operating in zero-gap configurations. Therefore, implementing stability tests in realistic device configurations is essential to assess compounded instability from all components, including the catalyst.2,4

Our group has developed and optimized a lab-scale electrochemical flow cell for alkaline water electrolysis (AWE), refined over four years of dedicated research (Figure 1a).4–7 This work outlines the operation of this device in a laboratory environment, focusing on accelerating the evaluation of electrocatalytic materials and their durability in alkaline conditions. We examined the performance of this lab-scale electrolyzer under industrially relevant conditions, including varying temperatures (Figure 1b). We examined the stability of three standard electrocatalytic materials to demonstrate the electrolyzer performance under fluctuating current conditions, including a benchmark NiFe anode for the oxygen evolution reaction (Figure 1c) and nickel nitride (Ni3N) precatalyst (Figure 1d). Furthermore, we propose a standardized protocol for assessing electrocatalysts under fluctuating and reverse currents, contributing to the understanding of catalyst deactivation. This initiative marks a significant advancement in AWE electrocatalysis research. Our goal is to establish an effective and straightforward protocol for evaluating and validating electrocatalysts in AWE, fostering accurate performance comparisons.

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Figure 1