Modelling and experiment towards the design of mesoporous organic-inorganic hybrid adsorbents

Templated mesoporous solids can readily be prepared with organic functionalities lining the silicate framework by co-condensation of triethoxysiloxanes during synthesis and Subsequent removal of the surfactant template. It is therefore possible to manufacture such materials with tailored pore geometry and surface chemistry to effect separations of gas mixtures.

The synthesis process and the adsorption behaviour of ordered mesoporous silicas and organosilicas is studied experimentally and by molecular simulation. The mesoporous solids MCM-41 and SBA-2, prepared with and without phenyl groups as organic functionalities, have been characterised structurally (TEM, NMR, XRD) and by adsorption of nitrogen and hydrocarbons. Atomic-scale models of the materials have been generated by a kinetic Monte Carlo simulation of the condensation of silica from Solution and subsequent calcination. Adsorption in these models is simulated by Grand Canonical Monte Carlo simulation and compared to the experimentally observed adsorption behaviour oil MCM-41, giving good agreement between simulation and experiment. Here we report these results and the first steps in applying the molecular simulation methods we have developed as tools for the design of selective, ordered mesoporous silica and organosilica adsorbents.