An Integral Metric for Evaluating Electrocatalytic Activity

ENG: This study introduces an integral metric of electrocatalytic activity, which is based on the comparison of the area under the polarisation curve in current density vs overpotential coordinates over a specific chosen overpotential range. This metric is applied to evaluate and compare several electrocatalysts, allowing for a more comprehensive understanding of electrocatalytic performance. Unlike traditional metrics, which characterise electrocatalyst behaviour under specific conditions (e.g. a particular overpotential or current density), the proposed integral metric provides a broader evaluation over a wide operational range. This approach is particularly useful for electrocatalysts with different Tafel slopes and polarisation characteristics. The metric is shown to be invariant to the shape of the polarisation curve and can be applied even when the exact form of the analytical dependence is unknown. The application of this metric holds promise for both fundamental studies in electrocatalysis and for practical applications in selecting the most efficient electrocatalysts for various technological processes.