Porous SiO2 Nanospheres Modified with ZrO2 and Their Use in One-Pot Catalytic Processes to Obtain Value-Added Chemicals from Furfural

Abstract

Porous SiO2 nanospheres were modified with different loadings of ZrO2 to obtain catalysts with a Si/Zr molar ratio from 2.5 to 30. These materials were characterized by X-ray diffraction, transmission and scanning electron microscopies, N2 adsorption–desorption at −196 °C, X-ray photoelectron spectroscopy and pyridine and 2–6-dimethylpyridine thermoprogrammed desorption. The characterization of these catalysts has revealed that a high proportion of Zr favors the formation of Lewis acid sites, which are implied in catalytic transfer hydrogenation processes, whereas the low Brönsted acidity promotes a dehydration reaction, being possible to give rise to a large variety of products from furfural through consecutive reactions, such as furfuryl alcohol, i-propyl furfuryl ether, i-propyl levulinate, and γ-valerolactone, in a range of temperature of 110–170 °C and 1–6 h of reaction.