Catalytic hydrogenolysis of sorbitol to glycols over chromium oxide silica: Effect of chromium loading

Abstract

Cr2O3-SiO2 (CrSi) catalysts were prepared using the sol-gel method with varying Cr2O3 loadings (5%, 10%, 15%, 20%, and 25% by weight). The physical properties of the synthesized catalysts were characterized through N2 physisorption analysis, X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM). Additionally, NH3-TPD analysis was employed to assess the acidity of the catalysts. The results indicated the presence of ordered mesopores with uniform pore sizes in the synthesized catalysts. The 20CrSi catalyst exhibited high total acidity, which correlated with its catalytic performance. The catalytic activities of the synthesized samples were tested in the sorbitol hydrogenolysis reaction to produce propylene glycols (PG) and ethylene glycols (EG) in a stirred high-pressure reactor under various process conditions. It was found that 20CrSi catalyst recorded maximum sorbitol conversion (70.08%) at optimum reaction condition. The catalyst was reusable up to 5 times with only a minor activity loss. This work contributes to sustainable and green chemical synthesis from renewable sources, offering insights into catalyst design for efficient glycol production.