TY - CONF A1 - Muhammad, R. A1 - Greiser, Sebastian A1 - Kosslick, H. A1 - Ibad, F. A1 - Jäger, Christian A1 - Rabeah, J. A1 - Schulz, A. T1 - Influence of the of dealumination and porosity on the acid sites of natural zeolite clinoptilolite N2 - Heavy feedstock from crude and bio oil is a widely available and renewable resource for production of fuel and starting materials for other organic valuables by cracking or hydrocracking. Catalytic processing of heavy feedstock can meet the increased demand of energy up to a great extent. It requires the application of acidic catalysts like zeolites. However, the used synthetic catalysts are difficult to recover and reuse and are mostly spent. The use of natural zeolite as spent catalysts may open new perspectives in the chemical use of heavy feed feedstock by chemical conversion. Natural zeolites are not expensive, widely available and environment friendly. Clinoptilolite is the most abundant natural zeolite. Clinoptilolite has a crystalline structure with a defined micropore system of medium size showing unique ion exchange and sorption properties. However, it is catalytically active only in the H-form. Also certain porosity is required for improvement of the accessibility of active sites. This paper deals with the tuning of acid properties and of the mesoporosity of the clinoptilolite by variation of the Si/Al framework ratio, extra-framework aluminum and modification of the porosity by specific acid and water vapor treatment. The preparation of hierarchical pore structures containing interconnected micro-meso-macropores is an important factor influencing the catalytic performance. The obtained materials have been characterized by XRD, TEM, FTIR, Raman, TG/DSC. The chemical composition has been determined by ICP-AES. The porosity have been investigated by nitrogen adsorption desorption measurements. The acidity has been measured by Ammonia-TPD. The extent of dealumination, stability of the clinoptilolite against acid treatment and the change in the nature of acid sites and their local structure has been studied by solid state 29Si and 27Al MAS NMR spectroscopy in detail. The catalytic activity has been investigated in the acetalization of benzaldehyde with 1,3-butanediol. The impact of the porosity, change of the Si/Al ratio as well as present Al species on catalytic properties will be discussed. T2 - 28. Deutsche Zeolith-Tagung CY - Giessen, Germany DA - 02.03.2016 KW - NMR KW - Zeolite KW - Clinoptilolite KW - Catalyst PY - 2016 AN - OPUS4-35886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -