Performance Optimization of Alkaline Water Electrolysis Via Catalyst Morphology Tuning and Novel Cell Design

Hydrogen is a basic energy carrier for numerous valuable industrial products. Green hydrogen produced using renewable electricity and water electrolysis is pivotal in advancing a decarbonized sustainable energy ecosystem. Two primary electrolysis technologies, alkaline water electrolysis (AWE) and polymer electrolyte membrane water electrolysis (PEMWE), have demonstrated a viable commercial perspective. AWE is particularly well-suited for large-scale deployment, especially at the gigawatt scale, due to low capital cost and long lifetime. 1. The performance of AWE is largely determined by the effectiveness of nickel-based oxygen evolution reaction (OER) catalysts and PGM-based or PGM-free hydrogen evolution reaction (HER) catalysts. To enhance the catalyst activity and cell performance, we meticulously control morphology and chemical composition of the catalysts. Cell testing was conducted in cells of various active areas (5, 25, and 50cm2) to demonstrate the result consistency and scalability. An innovative cell design, incorporating a reference hydrogen electrode in both cathode and anode, enabled the real-time acquisition of half-cell polarization curves during tests. This configuration proved valuable information to identify performance limitations in the single cells, thus guiding effective cell design and optimization. Furthermore, a cell comprising Ni-based anode and PGM cathode demonstrated remarkable stability. 1. Schalenbach, Aleksandar R. Zeradjanin, Olga Kasian, Serhiy Cherevko, and Karl J.J. Mayrhofer, Int. J. Electrochem. Sci. , 1173–1226 (2018).