Porous Al2O3-pillared bentonite synthesized by sonochemistry and its performance as a catalyst in diethyl ether production via ethanol dehydration

This research investigated the performance of bentonite and Al-PILC as catalysts in ethanol conversion to diethyl ether through a dehydration reaction. The natural bentonite was intercalated with the pillaring agent Keggin-ion Al13 to obtain Al-intercalated bentonite. Al-intercalated bentonite has been synthesized using conventional stirring and ultrasonication. Al-intercalated bentonite was calcined at 400 °C for 4 h to produce Al2O3 pillared bentonite (Al-PILC). The dehydration reaction was conducted using a 0.2 g catalyst and 10 mL of ethanol with a nitrogen gas flow rate of 20 mL/min at various reaction temperatures (200, 225, and 250 °C) using a fixed bed microreactor. The characterization results reveal that Al-PILC synthesized by sonochemistry exhibits significantly higher surface area and total acidity values than bentonite and Al-PILC synthesized by conventional methods because of the formation of stable Al2O3 pillars in the interlayer spaces of bentonite. The sonochemically synthesized Al-PILC produces optimum ethanol conversion and diethyl ether yield of 46.05% and 41.11%, respectively. The conversion of ethanol and diethyl ether yield reaches an optimum result at 225 °C. Based on this study, the pillarization of bentonite using Al2O3 can enhance its catalytic properties toward diethyl ether production. Graphical abstract: (Figure presented.)