| Thermal and Crystalline Stability of Silica-Tungsta/Titania Particles Made by Flame Spray Pyrolysis | ||
| Rainer Jossen1, Martin C. Heine2, Kamal M. Akhtar3 and Sotiris E. Pratsinis2, (1)Department of Mechanical and Process Engineering, Swiss Federal Institute of Technology Zurich, Particle Technology Laboratory, Sonneggstrasse 5, Zurich, CH-8092, Switzerland, (2)Particle Technology Laboratory, Swiss Federal Institution of Technology Zurich, Sonneggstrasse 5 NO H 19, Zurich, 8092, Switzerland, (3)Research Center Baltimore, Millennium Chemicals Inc., 6752 Baymeadow Drive, Glen Burie, MD 21060 The effect of doping with silica flame-made WO3/TiO2 powders (anatase, 100 m2/g) on their specific surface area, crystallinity and catalytic activity was investigated. The silica content was 0-5 wt% while tungsta was constant at 10 wt%. The structural and chemical properties of these nanosized powders were analyzed by nitrogen adsorption (BET), X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electron microscopy (TEM) and Raman spectroscopy. The thermal and crystal stability was improved by adding up to 5 wt% silica. After calcination for 20 hours at 700°C in air, the thermally most stable powder conserved a SSA of 90 m2/g and 96 wt% of the anatase. Tungsta form thin polymeric layers (~1 nm) on the surface of the titania support. Extended Abstract Status: File Uploaded | ||