Relation between homogeneous acid catalysis and ion exchange resins using a test reaction

Abstract

The kinetic analysis of the depolymerization of trioxane with a strong acid resin supplied as commercial catalyst has been performed. Experiments at different speeds of rotation lead to the conclusion that the external mass transfer is not the controlling step, and the influence of the temperature on the reaction rate indicates the chemical reaction as controlling step. A relation between the resin load and the Hammett acidity function can be obtained after comparison between the homogeneous catalyzed reaction and the resin catalyzed reaction. This relation seems to be useful in order to establish an equivalence between catalytic resins and homogeneous catalyzed reactions for practical purposes. Two parameters, ϱ, which describes the quantitative relation between acidity and resin concentration and Δ E/R, which takes account of the small difference between activation energies in homogeneous acid catalysis and heterogeneous acid (ion exchange) catalysis are able to describe the feasibility to use acid resins in homogeneous acid catalyzed reactions. The studied system seems to have an application as a test reaction for the evaluation of catalytic resins.