COMPOSITION BASED ON CERIUM, ZIRCONIUM AND TUNGSTEN, PREPARATION PROCESS AND USE IN CATALYSIS

摘要

The invention relates to a composition based on cerium, zirconium and tungsten and which has a content, expressed as oxide, of cerium of between 5 and 30%; of tungsten of between 2 and 17% and the balance of zirconium. After ageing at 750°C in an air atmosphere containing 10% water, it has a two-phase crystallographic structure comprising a tetragonal zirconia phase and a monoclinic zirconia phase, with no presence of a crystalline phase containing tungsten. This composition may be used as a catalyst, especially in an SCR process.