Temperature-Jump Relaxation Magic-Angle Spinning NMR Study of the Methyl tert-Butyl Ether Reaction in a Boron Pentasil Zeolite

Temperature-jump relaxation magic-angle spinning NMR experiments are for the first time applied to study a heterogeneously catalyzed reaction. A temperature jump from 20 to 100−150 °C creates a nonequilibrium state of the system consisting of methyl tert -butyl ether (MTBE), methanol, and isobutene, which are adsorbed on a boron pentasil zeolite in a sealed glass tube. The rate constants of MTBE decomposition and formation were determined, and the corresponding apparent energies of activation are 51 and 32 kJ mol - 1, respectively. The NMR findings are in agreement with experimental results obtained in a fixed bed reactor or in an autoclave.