Lewis acid Sn-BEA with tunable morphology and hydrophobicity was successfully synthesized by recrystallization of post-synthesized Sn-BEA (Sn-BEA-PS) using ammonium fluoride (NH4F) and tetraethylammonium bromide (TEABr). This recrystallization method includes the dissolution of crystalline zeolite BEA by fluoride ions and the reassembly of fragmented silica species into defect-free zeolite framework in the presence of TEA ions. The recrystallization method significantly reduced silanol nests, resulting in improved hydrophobicity for the Sn-BEA samples. In addition, the density of open Lewis acid Sn sites, dominant active sites for glucose (C6 sugar) isomerization, was increased after the recrystallization. As a result, the Sn-BEA made by the recrystallization approach (Sn-BEA-RC) showed a 2.5 times higher rate for aqueous glucose isomerization, compared with Sn-BEA-PS. The recrystallization method is a facile and reliable approach to not only improve hydrophobic property of Sn-BEA with tailored crystal morphology, but also offer open Sn site environment, in turn, leading to an improved catalytic activity.

Fabrication of Lewis acid Sn-BEA with tunable hydrophobicity and morphology for cellulosic sugar isomerizations

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.