Overcoming Artifacts in Cyclic Voltammetry through the Use of Multiple Scan Rates and Potential Windows

Abstract

A new technique for overcoming artifacts in the determination of electrochemical surface area (ECSA) from cyclic voltammetry (CV) data has been demonstrated. Using a CV measured at low scan rate to calculate a background, data at other scan rates can be corrected to largely eliminate artifacts due to Concentration Cell and H2 crossover effects. Additional artifacts can be minimized by limiting the upper potential limit of the CV to about 0.6V, and by using a separate scan of the capacitance region (from about 0.35 - 0.6V) to determine the electrode capacitance. Data from this "Background-Corrected" CV technique compared favorably to established techniques of CO Stripping and Flooded CVs, showing a good correlation to Pt loading, comparable adsorption/desorption peak symmetry, and reasonable resolution of features in the scans themselves. The new technique is more easily automated than the alternatives, requiring no additional gas-switching, temperature changes, or injection of liquid water. It also imposes no constraints on the RH at which measurements can be made.