IR spectroscopic detection of the propene species formed via the interaction of copper-ion-exchanged MFI-type zeolite with propane at 573 K

•A characteristic IR band was detected by the contact of CuMFI and C3H8 above 573 K.•The C3H6 species were produced by the interaction of CuMFI with C3H8 above 573 K.•CuMFI exhibited the irreversible adsorption property for C3H8 at 573 K. Copper-ion-exchanged MFI-type zeolite (CuMFI) has been reported to effectively interact with propane (C3H8) even at room temperature and this sample has the potential of being used as a CH bond activation material. In this study, we examined the interaction between CuMFI and C3H8 at various temperatures. The adsorption isotherms of C3H8 showed that CuMFI exhibits strong adsorption at 573 K. For CuMFI treated at temperatures above 573 K under a C3H8 atmosphere, a characteristic infrared (IR) absorption band was detected at 1542 cm–1, which was hardly observed for other samples such as NaMFI and HMFI. This band was assigned to the CC stretching vibration mode of propene (C3H6) species adsorbed on CuMFI. Therefore, the C3H6 species were produced by the contact of CuMFI with C3H8 at approximately 573 K; propane dehydrogenation occurred. This temperature (573 K) was lower than the reaction temperature for propane dehydrogenation, which had been reported to be temperature around 773 K or higher.