A Scan Rate Dependent Determination of Platinum Areas

Abstract

Platinum areas are determined by standard cyclic voltammetric techniques in , at scan rates between 20 and 100 mV/sec. A linear extrapolation of the measured charge in the H adsorption region to infinite scan rates eliminates the charge associated with the background evolution reaction. The technique allows the direct determination of the potential of full H coverage of the Pt, and hence, the generation of adsorption isotherms. The separation of evolution from H adsorption charges is shown to be more significant in the measurement of Pt areas on gas diffusion electrodes than on platinized Pt electrodes.