Hydrothermolysis of carbohydrates using metal supported on aluminosilicate

Abstract

Mesoporous silica SBA-15 was synthesized by hydrothermal method using triblock P123 (poly(ethylene oxide)20-poly(propylene oxide)70-poly(ethylene oxide)20) copolymer as a structure directing agent. The gel molar composition of SBA-15 was 1.0 TEOS: 0.0165 P123: 6.95 HCl: 140 H2O. The gel was crystallized at 100°C for 48 h. The Al-SBA-15 was synthesized by incorporating SBA-15 with aluminium via post synthesis. In addition, the Ni and Ru metal supported on SBA-15 and Al-SBA-15 were prepared by aqueous wet impregnation method. The synthesized materials were characterized by X-ray powder diffraction, nitrogen sorption analysis, solid state 27Al-nuclear magnetic resonance, scanning electron microscopy equipped with energy dispersive spectrometer, and transmission electron microscopy. Synthesized catalysts were applied in hydrothermolysis of carbohydrates using glucose, sucrose, and starch as starting materials. The various reaction parameters such as starting material type, catalytic type, catalytic amount, and temperature were studied. From the results, the optimum condition for glucose over 20%Ru-ZSM-5 in amount of 15 wt.% of starting material at 200°C for 1 h which gave the maximum levulinic acid selectivity as 44.0%. The optimum condition for sucrose over 20%Ru-Al-SBA-15 in amount of 15 wt.% of starting material at 200°C for 1 h which gave the maximum levulinic acid selectivity as 40.8%. The optimum condition for starch over 20%Ru-Al-SBA-15 in amount of 10 wt.% of starting material at 300°C for 1 h which gave the maximum levulinic acid selectivity as 38.6%.