Evaluation of Tafel–Volmer kinetic parameters for the hydrogen oxidation reaction on Pt(1 1 0) electrodes

Abstract

Modelling of PEM fuel cells has long been an active research area to improve understanding of cell and stack operation, facilitate design improvements and support simulation studies. The prediction of activation polarization in most PEM models has concentrated on the cathode losses since anode losses are commonly much smaller and tend to be ignored. Further development of the anode activation polarization term is being undertaken to broaden the application and usefulness of PEM models in general.Published work on the kinetics of the hydrogen oxidation reaction (HOR) using Pt(hkl) electrodes in dilute H2SO4 has been recently reassessed and published. Correlations for diffusion-free exchange current densities were developed and empirical predictive equations for the anode activation polarization were proposed for the experimental conditions of the previously published work: Pt(100), Pt(110) and Pt(111) electrodes, pH2 of 1atm, and temperatures of 1, 30 and 60°C. It was concluded that the HOR on Pt(110) electrodes followed a Tafel–Volmer reaction sequence.The aim of the present paper is to generalize these Tafel–Volmer correlations, apply them to published data for Pt(110) electrodes and further develop the modelling of anode activation polarization over the range of operating conditions found in PEMFC operation.