New MoO3-CeO2-ZrO2 and WO3-CeO2-ZrO2 nanostructured mesoporous aerogel catalysts for the NH3-SCR of NO from diesel engine exhaust

New MoO3 or WO3 modified CeO2-ZrO2 aerogel catalysts were elaborated using the sol gel method combined to supercritical drying for NO-SCR by NH3 in excess of O2. XRD, N2-Physisorption, NH3-TPD, H2-TPR and DRUV-Vis spectroscopy used analyse samples. The results reveal that all powders (ZrO2, CeO2-ZrO2, MoO3-ZrO2, WO3-ZrO2, MoO3-CeO2-ZrO2 WO3-CeO2-ZrO2), calcined at 500 °C, are nanostructured mesoporous materials, developing essentially diffraction peaks ZrO2 tetragonal phase, which was stabilized presence cerium. Ce, Mo W species found highly dispersed on zirconia surface, their nature diverse interactions developed between them affect crystallites size ZrO2, acidity, reducibility, surface oxygen mobility influence extremely SCR activity. Higher performances obtained, 200 over new ternary WO3-CeO2-ZrO2 compared corresponding binary systems (CeO2-ZrO2, MoO3-ZrO2 WO3-ZrO2). This discloses a synergism related existence strong Ce?Mo Ce?W. Interestingly, above 90 % NO conversions into N2 (? 97 %) achieved 350 °C most efficient catalyst.