Channel flow double electrode (CFDE) was applied to study palladium dissolution during potential cycling in 0.5 M H2SO4 solution at 25 degrees C. In the CFDE, Pd ions (Pdn+) dissolved from a Pd working electrode were detected by reducing them to Pd on a gold collector electrode, which was placed at the downstream. The detection of the Pd dissolution by the collector current was confirmed by (Electron Probe Micro Analyzer) EPMA analysis of the collector electrode surface. In anodic scan, gradual rise of the collector current till 0.7V indicated Pd dissolution. The dissolution was confirmed by EPMA. Anodic as well as cathodic dissolution was confirmed when potential cycling was done till 0.8 V. Dissolution of palladium was found to increase anodically as well as cathodically when upper limit of polarization was increased. From collector current and the results of EPMA, the dissolution mechanism is proposed. (C) 2012 Elsevier Ltd. All rights reserved.