Hierarchical EMT structured zeolites as improved catalysts for glycerol dehydration

A fast and simple post-synthesis method for creating secondary mesoporosity in EMT zeolites was developed using an ammonium fluoride / cetyltrimethylammonium bromide (NH4F/CTAB) solution at low temperature with ultrasound irradiation. This strategy is shown to be highly effective for producing hierarchical EMT structured zeolites through the etching of both Si and Al species. The catalytic performance of these materials were assessed using glycerol dehydration as a reaction test, which is in addition a relevant reaction due to the high amounts of glycerol generated as a by-product of biodiesel production. The resulting hierarchical EMT structured zeolites exhibited improved catalytic activity and high selectivity towards acrolein (around 80 %). This innovative approach creates new opportunities for using hierarchical EMT structured zeolites in processes related with biodiesel manufacture. [Display omitted] •Simple and fast post-synthesis treatment to achieve hierarchical EMT zeolites.•NH4F/CTAB solution preserves the zeolitic framework getting narrower mesopores.•Mesoporosity/acidity synergism in hierarchical EMT promotes catalytic improvement.•Use of hierarchical EMT in glycerol dehydration was reported for the first time.•Hierarchical EMT structured zeolites show around 80 % acrolein selectivity.