Transport Properties of Guest Molecules in Mesoporous SBA-15 Materials - A PFG NMR Study

1. Introduction Catalysts are among the most important materials in modern industry. Hundreds of millions of tonnes of catalysts per year are produced in order to convert " raw " materials into value-added products. Continuously new catalysts with improved chemical and optimized transport properties are developed. At the present time there is an increasing interest in SBA-15 type materials due to their unique internal porous structure, consisting of an array of straight non-intersecting channels with diameters of several nanometres where chemically active centres can be incorporated. Such pores should provide an increased rate of reactant supply and product removal from the catalyst. In the present work, the pulsed field gradient nuclear magnetic resonance (PFG NMR) method has been applied to study the mobility of guest molecules in SBA-15.