Effects of Electrochemical Parameters on the Evaluation of Nickel-Based OER Catalysts under Alkaline RDE Conditions

High Resolution Image Download MS PowerPoint Slide The oxygen evolution reaction (OER) is a major efficiency bottleneck in electrochemical water splitting, and the search for earth-abundant catalysts has gained significant momentum. Yet, the absence of standardized testing procedures for activity and stability often produces inconsistent and non-comparable results, obscuring true material advances. In this work, we systematically evaluate how electrochemical testing parameters and setup configurations influence the benchmarking of nickel-based catalysts under alkaline rotating disk electrode (RDE) conditions. Using polycrystalline Ni, Ni/NiO nanoparticles, and Ni/NiO/C composites as model systems, we identify critical factors, including counter electrode choice, electrolyte composition, and activity/stability protocols, that can substantially alter the measured performance. To demonstrate the broader relevance, three reported high-performance catalysts, NiFeP, NiFeMo oxide, and NiFeCu oxyhydroxide, were reassessed under our unified protocol, revealing pronounced discrepancies from literature values and underscoring the protocol dependence of reported activity. These insights lead to a practical RDE testing framework that minimizes external variables, improves reproducibility, and enables more reliable cross-study comparisons for the advancement of alkaline OER catalysts.