Dynamic Investigation of the Role of the Surface Sulfates in NOx Reduction and SO2 Oxidation over V2O5−WO3/TiO2 Catalysts
| Autor: | Luca Lietti, Pio Forzatti, Carlo Orsenigo, F. Bregani, Enrico Tronconi |
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| Rok vydání: | 1998 |
| Předmět: |
inorganic chemicals
Thermogravimetric analysis General Chemical Engineering Inorganic chemistry Selective catalytic reduction General Chemistry Heterogeneous catalysis complex mixtures Decomposition Industrial and Manufacturing Engineering Catalysis chemistry.chemical_compound chemistry Sulfur trioxide Fourier transform infrared spectroscopy NOx |
| Zdroj: | Industrial & Engineering Chemistry Research. 37:2350-2359 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/ie970734t |
| Popis: | Transient experiments performed over synthesized and commercial V2O5−WO3/TiO2 catalysts during catalyst conditioning and during step changes of the operating variables (SO2 inlet concentration and temperature) show that conditioning of the catalyst is required to attain significant and reproducible steady-state data in both the reduction of NOx and the oxidation of SO2 . The response time of conditioning for NOx reduction is of a few hours and that for SO2 oxidation is of several hours. Fourier transform infrared spectroscopy temperature programmed decomposition, and thermogravimetric measurements showed that catalyst conditioning is associated with a slow process of buildup of sulfates: the different characteristic conditioning times observed in the reduction of NOx and in the oxidation of SO2 suggest that the buildup of sulfates occurs first at the vanadyl sites and later on at the exposed titania surface. Formation of sulfates at or near the vanadyl sites increases the reactivity in the de-NOx reactio... |
| Databáze: | OpenAIRE |
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