Electrochemical evaluation of the real surface area of copper-zinc alloys

Accurate measurements of real surface area (RSA) are essential in fundamental electrocatalysis for evaluating the intrinsic activity of various materials. However, existing electrochemical methods for determining RSA values in metallic alloys, particularly those containing active metals, remain underexplored. This study critically assesses the efficacy of capacitance measurement techniques for calculating RSA values in copper-zinc alloys, which are commonly employed as electrocatalysts for CO₂ reduction. We investigate optimal conditions for estimating RSA through cyclic voltammetry, focusing on electrolyte selection and appropriate potential ranges to ensure reliable RSA assessments. Additionally, we emphasize the necessity of using suitable reference samples for accurate specific capacitance calculations. Our findings reveal that potential uncertainties arising from the use of inappropriate reference samples across different Cu-Zn compositions can reach an order of magnitude, rendering them unsuitable for electrocatalytic studies. This research highlights the need for robust surface area quantification techniques to reduce uncertainties in reporting the activities of alloy-based materials in various electrochemical applications.