DYNAMICAL OBSERVATION OF THE CATALYTIC ACTIVATION OF METHANOL IN ZEOLITES

The adsorption of methanol in the zeolites chabazite, ferrierite and s ilicalite has been studied using first principles molecular dynamics s imulations. The study includes an investigation of the effect of both loading and temperature. At low coverage, methanol forms a hydrogen bo nded complex in chabazite and silicalite but proton transfer appears t o be stable in ferrierite when the methanol is in the eight-ring side channel. As the loading increases the methoxonium cation becomes the s table species and a surprisingly large weakening of the C-O bond occur s due to dynamical effects which may explain the enhanced susceptibili ty of the methanol to nucleophilic attack. (C) 1998 Elsevier Science B .V.