Abstract Propane dehydrogenation over alumina-supported Pt-Sn catalysts has been studied in an oscillating microbalance reactor (TEOM). The kinetics of coke formation and the deactivation functions for the coking and the dehydrogenation reaction were determined. The selected model describes the formation of coke (measured as the mass increase) on the catalyst well over the entire temperature range studied (450–580°C), independent of whether hydrogen was present in the feed gas or not. A commercial Pt/Al2O3 catalyst (CK 303) showed a higher degree of deactivation although the coking rate was lower. The initial activity is difficult to determine due to rapid initial deactivation. A model based on fitting the turnover frequency against the measured coke deposition (as opposed to time on stream) is found to give improved estimates of the initial activity.