Reformate hydrogen contains many impurities, some are well known while others have been less studied. Hydrocarbons are possible impurities in reformate hydrogen and are among those less studied. This study if aimed at alkenes, with special focus on propene. Adsorption and desorption on the Pt catalyst is studied using stripping cyclic voltammetry combined with mass spectrometry. The results show that although the effect of propene in the presence of hydrogen is expected to be minimal, adsorption and blockage of catalytic sites cannot be ruled out. A small amount of ad-species is formed on Pt at low adsorption potentials, and in the presence of hydrogen, although suppression of the hydrogen desorption peak was minimal if hydrogen was adsorbed on the Pt catalyst prior to exposure.