Engineering Active Sites for Next-generation Water Splitting Electrocatalysts: From Mechanistic Studies to High-performance Materials

This thesis investigates catalyst materials for proton exchange membrane water electrolysis and their performance under model and real operating conditions. It shows that cobalt-based oxide catalysts lack the stability required for practical performance. The research therefore progresses to ruthenium oxide–based, and low-iridium mixed-metal electrocatalysts, evaluated under both aqueous model conditions and in real single-cell electrolysers optimised in this work. It also establishes a dedicated cell design and testing protocol and demonstrates that model conditions do not reliably predict device behaviour. By integrating materials development with electrolyser engineering and validation, this thesis provides a practical framework for durable and efficient hydrogen production.