Aerosol route to nanostructured WO3-SiO2-Al2O3 metathesis catalysts: Toward higher propene yield

Aerosol processing is presented as a powerful new method to yield in one step highly efficient olefin metathesis catalysts. Combined with sol-gel chemistry, evaporation induced self-assembly and polyanions, it allows a fine tuning of the dispersion of WOx species and the generation of acidic matrices which are key parameters controlling the formation of active metathesis sites. These spray dried catalysts are characterized by N-2-physisorption, XRD, TEM, NH3-TPD, TPO, TPR, ICP-AES and systematically compared to relevant reference catalysts prepared by impregnation methods on different carriers (silica, alumina and silica-alumina). Tested in the industrially relevant cross-metathesis of ethene and 2-butene to propene, the new catalyst outcompetes reference catalysts, reaching 68 mmol(propene) g(-1) h(-1) at 250 degrees C. By-products formed by isomerization reactions remain very low and high propene yields (39%) are reached. (C) 2013 Elsevier B.V. All rights reserved.