Ex situ study of chloride contamination on carbon supported Pt catalyst

► We tested the Cl− effect on Pt/C catalyst using EQCM method. ► The dissolution of Pt resulted in an electrochemical surface area loss. ► SEM images showed agglomeration on the catalyst surface after potential cycles with Cl−. The effect of ppm levels of chloride ions on a carbon supported platinum catalyst was examined using an ex situ electrochemical quartz crystal microbalance (EQCM) method. The dissolution of Pt as chloride complexes and the adsorption of chloride ions resulted in a loss of electrochemical surface area (ECSA) by 4%, 7% and 13% for the respective chloride concentrations of 500ppm, 1000ppm and 2000ppm. Catalyst durability was examined by cyclic voltammetry (CV) and scanning electron microscopy (SEM) in the presence of 1000ppm chloride. The beginning of life (BOL) ECSA of 8.1cm2cm−2 was significantly reduced to an end of life (EOL) ECSA of 3.2cm2cm−2 after cycling in the presence of 1000ppm chloride.