Nanocrystalline H-RTH Zeolite: An Efficient Catalyst for the Low-Temperature Dehydration of Ethanol to Ethene

The low-temperature dehydration of bioethanol is an environmentally benign route to ethene production. Here we compare the catalytic properties of a series of cage-based small-pore zeolites with different framework structures, acid strengths, and/or crystallite sizes for ethanol dehydration at 200 °C under wet conditions (H₂ O/EtOH=0.2). Among the zeolites studied here, nanocrystalline H-RTH was found to be considerably more effective than H-mordenite, the best catalyst for this reaction known to date, which can be rationalized by product shape selectivity. Whereas the acidity of this zeolite also plays a crucial role in selectively forming ethene, its nanocrystallinity is primarily responsible for the observed high catalyst durability.