Microcatalytic study of the depolymerization of 2,4,6-trimethyl-1,3,5-trioxan (paraldehyde) over mordenite surfaces

Abstract

The catalytic depolymerization of paraldehyde (2,4,6-trimethyl-1,3,5-trioxan) to acetaldehyde over Na⁺-, Ca²⁺- and La³⁺-exchanged mordenites has been investigated by means of conventional pulse-flow microcatalytic chromatography. The injection port of a gas chromatograph was used as a microcatalytic reactor chamber. The apparent activation energy was found to be 37.0 kJ mol^–1 for NaM and 16.0 kJ mol^–1 for CaM and LaM. The mordenite-catalysed depolymerization of paraldehyde fits the Langmuir–Hinshelwood kinetic model, which can be described by the following pathway (see Discussion for symbols): (PA)_g+Σ [graphic omitted] [PA ⋯Σ]* [graphic omitted] [AA ⋯Σ]* [graphic omitted] (AA)_g+Σ