Design of sustainable catalysts by post-synthesis modification of germanosilicate zeolites

1 Abstract Due to the presence of small structural units (e.g., D4R, D3R), the frameworks of germanosilicate zeolites are generally characterized by high pore volumes and multidimensional/extra-large pore systems, making them especially suitable in processing bulky molecules (in particular, involved in biomass-derived compounds valorization). However, weak acidity, low hydrothermal stability and high cost of Ge significantly limit the practical use of Ge-containing zeolites. This thesis is aimed at design of sustainable germanosilicate zeolite-based catalysts of modifiable chemical composition and tunable porosity for relevant acid-catalyzed reactions, such as ketalization of polyols, epoxidation of olefins, Baeyer-Villiger oxidation of cyclic ketones and Meerwein-Ponndorf-Verley reduction of aldehydes. Germanosilicate zeolites of different structures, including medium-pore ITH, large pore IWW, extra-large pore UTL and *CTH, were thoroughly characterized using a combination of techniques (i.e., XRD, physisorption, electron microscopy, chemical analysis, among others) and subjected to different post-synthesis modifications to address synthesis-structure-activity relationships in the designed germanosilicate-zeolite based catalysts. In ketalization of glycerol to solketal, weak acid centers of IWW and UTL..