Hetero-mixed TiO2-SnO2 interfaced nano-oxide catalyst with enhanced activity for selective oxidation of furfural to maleic acid

Abstract

Herein we report on the catalytic activity of hetero-mixed TiO2-SnO2 nano-oxide catalyst for the selective liquid-phase oxidation of furfural to maleic acid using H2O2 oxidant. The high surface area and strong interaction of the two oxides with modified electronic structure manifested enhanced effective oxygen vacancies, and redox activity performance of the TiO2-SnO2 catalyst for furfural oxidation reaction. The structure of the catalyst was investigated by the powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transition electron microscopy (HRTEM), electron paramagnetic resonance (EPR) and Brunauer-Emmett-Teller (BET) surface area analyser techniques. The interfaced TiO2-SnO2 oxide catalyst was more catalytically active than its single counterpart SnO2 and TiO2 oxides to give a furfural conversion of 96.2% at up to 63.8% yield of maleic acid. The catalytic performance shown by TiO2-SnO2 present encouraging prospects for an economical solid metal oxide catalyst to access biobased maleic acid from renewable biomass-derived furfural.