Direct synthesis of the organic and Ge free Al containing BOG zeolite (ITQ-47) and its application for transformation of biomass derived molecules

Abstract

Aluminosilicate boggsite (Si/Al-BOG) has been hydrothermally synthesized without adding organic structure-directing agents (OSDAs) in the synthesis gel using the borosilicogermanium ITQ-47 (Si/B-ITQ-47) zeolite as seeds. The introduction of the costly and environmentally less benign phosphazene organic structure-directing agent is not required to grow the zeolite. Physicochemical characterization experiments show that Si/Al-BOG has good crystallinity, high surface area, tetrahedral Al³⁺ species, and acid sites. In order to test the catalytic performance of the zeolite, the synthesis of L,L-lactide from L-lactic acid was performed. Si/Al-BOG exhibits 88.2% conversion of L-lactic acid and 83.8% L,L-lactide selectivity, which are better than those of other zeolites studied up to now.