Methyl tert-Amyl Ether Synthesis Catalyzed by a Sulfonic Cation Exchanger: The Effect of the Degree of Hydration of the Cation Exchanger on the Catalytic Activity and Reaction Mechanism

Abstract

The catalytic properties of the fibrous sulfonic acid cation exchanger FIBAN K-1 in methyl tert-amyl ether synthesis are studied as a function of its water content. Reducing the degree of hydration of the cation exchanger to <2 H2O molecules per SO3H group diminishes the proportion of the desired product in the catalysate. According to 13C NMR data, protonation of methylbutenes in the air-dry cation exchanger phase (which contains 4 H2O molecules per SO3H group) involves [nH2O] ⋅ H+ species and is accompanied by olefin hydration and the formation of protonated tert-amyl alcohol.