Preparation of Ga\(_{2}\)O\(_{3}\)-modified sulfated zirconia mesopore and its application on cellobiose hydrolysis

Abstract

Heterogeneous catalyst plays vital role in biomass processing due to slow rate of biological and naturally pathway processes. Solid acid sulfated zirconia (SZ) is a promising catalyst with properties that can be tuned up. Sulfated zirconia was successfully modified by 2%, 5% and 10% (wt.) Ga2O3 (xGa-SZ; x = 2, 5 and 10) via template-assisted sol-gel method. The catalysts were characterized through various method (XRD, SEM-EDS and Gas Sorption analysis) and applied on hydrolysis of cellobiose, a model compound of cellulose. Diffraction pattern showed xGa-SZ formed completely tetragonal phase whereas un-promoted SZ contains mixed phase of monoclinic and tetragonal. Acidity evaluation via gravimetric method using ammonia as probe molecule indicates the Ga2O3 promoted sulfated zirconia has larger acidity. The SEM-EDS results confirmed the presence of Gallium element on the surface of promoted xGa-SZ. Gas sorption analysis shows specific surface area is improved (83 m2∙g-1 to 123 m2∙g-1) and increased pore radii (36 Å to 56 Å). The adsorption-desorption isotherm displayed pattern of meso-porosity material. At higher T and longer time, SZ yield more glucose than xGa-SZ. However, at shorter time, 2Ga-SZ and 10Ga-SZ show better hydrolysis performance. The solid acid 10Ga- SZ shows potential performance as heterogeneous catalyst for cellobiose conversion in modest conditions.