Revealing the Activity Mechanism of Sulfided Ni-Foam in Alkaline Water Electrolysis Under Industrial Conditions Using Operando X-ray Diffrac

Sulfided nickel foam has emerged as a highly promising electrode material for enhancing the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline water electrolysis. However, the fundamental mechanisms driving its improved performance, particularly under industrially relevant conditions, remain insufficiently understood. This study aims to elucidate the phase transformations occurring in sulfided Ni-foam electrodes during electrolysis, including start-up and shutdown cycles, through operando X-ray diffraction. Specifically, we will identify the active HER phases and investigate the correlation between the relative proportions of the crystalline phases such as α- and β-Ni(OH)₂ and catalytic activity. The insights gained will contribute to a deeper understanding of the structure-performance relationships in sulfided Ni-based electrodes, facilitating the development of optimized electrode materials and operational strategies for more efficient and durable elect