Iridium-based catalysts play a vital role in producing hydrogen through water electrolysis, a key process for a climate-neutral energy system. A team at HZB has developed the P2X catalyst, requiring only a fraction of the iridium content of commercial catalysts while demonstrating comparable efficiency and stability. The study conducted at BESSY II highlighted how the chemical environment of the P2X catalyst influences the oxygen evolution reaction, offering insights into its superior performance. With the demand for hydrogen expected to rise, reducing iridium usage is essential, making the P2X catalyst a promising advancement in sustainable hydrogen production. The research, published in ACS Catalysis, provides valuable information on the mechanisms of iridium oxide-based catalysts, contributing to the understanding of their behavior during electrolysis. Through innovative spectroelectrochemical analysis, the team uncovered the distinct pathways and structural changes that impact the catalysts' performance. This work not only furthers the development of efficient catalysts for hydrogen production but also emphasizes the importance of sustainable practices in energy generation and storage.