A dual acidic hydrothermally stable MOF-composite for upgrading xylose to furfural

Abstract

This work presents the development of a new hybrid material composed of metal-organic-framework, MIL-101 (Cr) and mesoporous tin phosphate nanoparticles. The phosphate groups of the composite impart Brønsted acidity, while the Cr and Sn atoms act as the Lewis acid sites, thus promoting it as a dual acid functionalized material suitable for solid acid catalysis of biomass. Simultaneously, the issues of hydrothermal stability and degradation in acidic medium as faced by pristine MIL-101 (Cr), have been fairly alleviated. In order to demonstrate our claims, the composite has been used as a solid acid catalyst for the dehydration of xylose to furfural. A remarkable performance of 86.7% furfural yield with 92.3% selectivity has been achieved in 180 min at 150 °C. The composite can sustain minimum of 10 cycles of run while pristine MIL-101 (Cr) loses its functional properties after 4 cycles of run. In presence of 35 ppt NaCl solution, the yield and selectivity improved to 92.4% and 96.6% respectively.