Solid acid catalysts

Using qualitative and quantitative models, including both short and long range effects, progress has been made in understanding acidity in zeolites, but limitations that still exist in measuring that acidity by use of probe molecules. The benefits and limitations of enlarging zeolite pores by means of MCM-41 structures have been outlined. Major advances have been made in improving the catalytic activity of heteropolyacids and ZrO2/So42−, as well as tackling the mechanism through which ZrO2/SO42− catalyzes hydrocarbon reactions. Finally, new advances have also been made in the preparation and potential as acid catalysts of organic—inorganic composites (Zr phosphates and phosphonates, polysiloxane, nafion—silica).