Highly dispersed Cs2O/SiO2 catalysts for selective intramolecular dehydration of ethylene glycol monoethyl ether to ethyl vinyl ether

Abstract

Intramolecular dehydration of ethylene glycol monoethyl ether (EGME) is a safe and green alternative for the synthesis of ethyl vinyl ether (EVE). A series of xCs₂O/SiO₂-T catalysts with highly dispersed Cs₂O species was prepared via incipient wetness impregnation and showed excellent catalytic performance in intramolecular dehydration of EGME to EVE. The xCs₂O/SiO₂-T catalysts were well characterized to illustrate the relationship between the component, structure and surface state of catalysts, and the catalytic properties. The results indicated that both Cs₂O contents and calcination temperatures strongly influence the surface acidic–basic properties of catalysts. Meanwhile, the surface Si–O–Cs species formed during the synthesis process was proved to reinforce the activity as well as the selectivity of xCs₂O/SiO₂-T catalysts. Under the conditions of 400 °C, atmosphere pressure, and WHSV = 0.56 h⁻¹, the 5Cs₂O/SiO₂-500 exhibited excellent stability with EGME conversion of ∼72.5% and EVE selectivity of ∼90%, respectively.