Navigating the complexities of electrocatalytic water splitting: a critical examination of pitfalls and considerations in performance evaluation

Despite the rapid rise of electrocatalysis research, notably in hydrogen and oxygen evolution reactions (HER/OER), the discipline is still plagued by discrepancies in testing, data reporting, and performance benchmarking. This review examines the most important but sometimes ignored factors influencing catalyst performance, ranging from electrode preparation and electrolyte contaminants to the complexities of Tafel slope extraction and Faradaic efficiency measurement. This review critically examines the limitations of frequently used metrics, including overpotential, electrochemically active surface area (ECSA), and Tafel slopes, and demonstrates how uncontrollable variables can significantly distort reported activity. This study emphasizes the critical need for standardization by comparing normalization methods (geometric area, catalyst mass, and ECSA-based), as well as investigating how electrochemical impedance spectroscopy, double-layer capacitance, and product selectivity measurements are frequently misapplied or misinterpreted. We also highlight the worrying absence of raw data sharing and reproducibility in the literature, which impedes meaningful comparison and slows technological advancement. Finally, we offer a thorough checklist and protocols to build a universal benchmarking technique. This assessment, which highlights both technological insights and systemic obstacles, serves as a road map for a more transparent, reliable, and expedited electrocatalysis discovery process.