Infrared spectroscopic study of ethylene adsorbed on silicalite: Experiments and molecular dynamics simulation

The present paper deals with a fundamental infrared (IR) study of the interaction of a gas on a microporous adsorbent at room temperature. Both in situ FTIR spectroscopy and molecular dynamics simulation were carried out to investigate the adsorption process of ethylene on a siliceous ZSM-5 zeolite at 300 K. Orthorhombic aggregates of 18 unit cells of silicalite and molecules of ethylene were simulated using a full atomic model. At a first step, FTIR spectra of the zeolite and the adsorptive were computed separately and compared with experimental spectra. At the second step, spectra of zeolite and ethylene adsorbed were calculated at different loadings and analyzed in shape, location and area, with regard to experimental results. Simulated and experimental data were in good agreement and characterized a continuous adsorption process.