Microwave-Assisted Heating for Dehydration of Ethanol to Ethylene Using HPW/SBA-15

Abstract

Catalytic dehydration of bioethanol using tungsten polyoxometalate (POM) clusters is a viable method for the sustainable production of ethylene, a valuable industrial chemical. The reaction process of ethanol dehydration on mesoporous-silica-SBA-15 (SBA-15)-supported heteropolyacids (HPAs) involves complex parallel-consecutive pathways, which differ from those involved in pure HPAs systems. Notably, the reaction progresses from the formation of diethyl ether at lower temperatures to the complete generation of ethylene at higher temperatures. To conserve energy, achieving high selectivity for ethylene at lower temperatures is crucial. In this study, we impregnated 12-tungstophosphoric acid into an SBA-15 catalyst, followed by microwave-assisted heating to obtain a catalyst that facilitates the dehydration of ethanol to ethylene. Experimental findings revealed that this catalytic technique achieves a reaction at lower temperatures than conventional thermal catalysis, exhibiting conversion rates and selectivity values exceeding 99%. Additionally, the influence of the substrate on the entire reaction process was elucidated by clarifying the reaction pathways using theoretical calculations.