1. Multistep biomass conversion reactions catalyzed with Sn in a partially dealuminated Beta framework

Multifunctional catalysis is key to convert biomass mols. into useful chems. [1, 2]​. A practical synthesis method is presented to synthesize Lewis acid Snβ-​type materials with Bronsted acid Al in the framework. This bifunctional material is used in multi-​step conversion reaction, which demand both Lewis acid as Bronsted acid catalytic sites. The material is synthesized according to a simple two-​step procedure existing of a partial dealumination of a com. available beta zeolite, creating silanol nests, and subsequent grafting of the dealuminated zeolite with SnCl4. Characterization of the materials with EXAFS, FT-​IR, UV-​VIS-​NIR DRS, Sn Mossbauer and 29Si, 27Al and 119Sn MAS NMR shows the presence of Bronsted acid framework Al and tetrahedral Lewis acid Sn sites. Catalytic properties of the material will be demonstrated for the isomerization of sugars mols. [3]​, and with recent data for Baeyer-​Villager type of reactions and for MPV-​type reactions in the conversion of trioses such as 1, 3 dihydroxyacetone (DHA) into Et lactate (ELA)​. Presence of Al in the material allows for a more facile conversion of DHA. Yet, too high of a Al-​content leads to a drop in selectivity due to side-​reactions. Materials contg. moderate amts. of Al showed record productivities (1774 g ELA.kgcatalyst-​1.h-​1 ) and TOF per Sn (118 mol ELA.mol Sn-​1.h-​1) up to 150​% of the Al-​free materials with similar Sn-​content. The bifunctional catalyst proved to be truly heterogeneous and recyclable without loss in activity. [1] Filip de Clippel, Michiel Dusselier, Ruben Van Rompaey, Pieter Vanelderen, Jan Dijkmans, Ekaterina Makshina, Lars Giebeler, Steffen Oswald, Gino V Baron, Joeri FM Denayer, Paolo P Pescarmona, Pierre A Jacobs, Bert F Sels, Journal of the American Chem. Society (2012) 134 (24)​, 10089-​10101.[2] F de Clippel, M Dusselier, S Van de Vyver, L Peng, PA Jacobs, BF Sels, Green Chem. (2013) 15 (6)​, 1398-​1430.[3] Jan Dijkmans, Dries Gabriels, Michiel Dusselier, Filip de Clippel, Pieter Vanelderen, Kristof Houthoofd, Annelies Malfliet, Yiannis Pontikes, Bert F Sels, Green Chem. (2013) 15 (10)​, 2777-​2785.status: publishe