University of Ulm researchers redefine nickel catalyst surface for water electrolysis

Researchers at the University of Ulm have identified the true nature of the catalytic surface used in alkaline water electrolysis. Using isotope labeling and surface-enhanced Raman spectroscopy (SERS), the team demonstrated that the active phase during oxygen evolution is nickel dioxide (NiO2), rather than the long-held assumption of nickel oxyhydroxide (NiOOH).

Nickel is a critical, cost-effective, and robust catalyst for producing climate-neutral hydrogen. However, significant energy losses often occur at the oxygen electrode. This study, published in Nature Catalysis, provides a more accurate understanding of the molecular structure of the catalyst surface under reaction conditions, which is essential for improving the efficiency of hydrogen production technology.