Rigor & Reproducibility in Electrocatalysis: Approaches and Considerations for Surface Area Normalization

Abstract Accurate normalization of electrocatalytic rates is essential for meaningful comparisons of catalytic performance and for distinguishing genuine improvements in intrinsic activity from effects arising from catalyst loading, surface roughness, or morphology. In practice, the inappropriate use of performance metrics and the absence of activity normalization have led to qualitatively incorrect conclusions about catalytic performance across multiple important electrocatalytic reactions. This motivates the need for careful consideration of what information different performance measures provide and under what circumstances their use is appropriate. Here, we outline a hierarchy of activity normalization strategies, ranging from geometric and mass activities, which are appropriate for device-level comparisons, to site-normalized rates, which enable the identification of active sites and comparison of intrinsic activity and benchmarking among electrocatalysts with different synthetic origins. We discuss common approaches for estimating electrochemically active surface area and for quantifying active-site densities, highlighting their key assumptions and limitations. We show that for well-studied and structurally simple catalysts, multiple complementary electrochemical approaches can yield consistent measures of surface area, allowing intrinsic activity conclusions that are robust to the specific normalization method used. In contrast, for more complex catalyst classes, fewer validated site-counting approaches exist, and quantitative comparison between techniques is less straightforward, underscoring the need for continued development and validation of normalization methods. Overall, this perspective aims to clarify the strengths and limitations of commonly used normalization strategies to promote more rigorous, reproducible, and meaningful assessment of electrocatalytic performance.