| Abstract
| - The pore structure formation in bentonite, pillared with a mixed sol of silicon and titanium hydroxides andtreated subsequently with quaternary ammonium surfactants, is investigated. The surfactant micelles act as atemplate, similar to their role in MCM41 synthesis. Because both the surfactant micelles and the sol particlesare positively charged, it is greatly favorable for them to form meso-phase assembles in the galleries betweenthe clay layers that bear negative charges. Besides, the sol particles do not bond the clay layers strongly asother kinds of pillar precursors do, so that the treatment with surfactants can result in radical structure changesin sol-pillared clays. This allows us to tailor the pore structure of these porous clays by choice of surfactant.The surfactant treatment also results in profound increases in porosity and improvement in thermal stability.Therefore, the product porous clays have great potential to be used to deal with large molecules or at highoperating temperatures. We also found that titanium in these samples is highly dispersed in the silica matrixrather than existing in the form of small particles of pure titania. Such highly dispersed Ti active centers mayoffer excellent activities for catalytic oxidation reactions such as alkanes into alcohols and ketones.
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