Preparation and characterization of sol-gel based catalysts for the selective catalytic reduction of NO with NH₃

The preparation of sphere-shaped silica supported vanadium catalysts was carried out by using various techniques. The silica support was prepared by the sol-gel process, developed by KEMA. After the sphere formatIon, drying and sintering steps, the spheres of controlled diameters can be impregnated and coated by existing techniques, such as: wet impregnation, the socalled monolayer adsorption, which was developed at the Twente University of Technology (The Netherlands) and the homogeneous deposition precipitation, developed at the State University of Utrecht. The characterization of the catalysts was carried out by using various methods such as: activity measurements with a conventional fixed-bed reactor coupled with a mass spectrometer, temperature programmed reduction, scanning electron microscopy, X-ray fluorescence, BET-sorption and mercury-porosimetry.