Preparation and characterization of SO4 2−/TiO2 and S2O8 2−/TiO2 catalysts

Production of Levulinic Acid from Cellulose Catalyzed by Environmental-Friendly Catalyst

Using solid acid catalyst for the levulinic acid (LA) production from cellulose is one of the promising methods for utilization of biomass. An environmentally friendly solid acid catalyst, sulfated TiO2 was prepared by precipitation-impregnation method and used to catalyze the production of levulinic acid from cellulose. The concentration of sulphuric acid had a remarkable influence on the construction and catalytic activity of sulfated TiO2. The influence of reaction temperature and catalyst dosage on levulinic acid yield was also investigated with the aim to obtain the highest yield of LA. The optimum condition for the highest yield of levulinic acid (27.2%) was achieved at 240 °C, 0.7g of sulfated TiO2 and reaction time of 15 min. The recycling test indicated that the catalytic activity of the catalyst had a slight decrease after being used two times.

Preparation of mesoporous titania solid superacid and its catalytic property

Mesoporous titania (TiO(2)) was synthesized by hydrothermal method using cetyltrimethyl ammonium bromide (CTAB) as a template and using anhydrous ethanol and tetra-n-butyl titanate (TBOT) as raw materials. Mesoporous titania solid superacid and nanosized titania solid superacid catalysts were prepared by wet impregnation method. The structure and property of as-prepared samples were characterized by means of XRD, FT-IR and N(2) physical adsorption. The esterification of salicylic acid with isoamyl alcohol and the condensation of cyclohexanone with ethylene were used as model reactions to test the catalytic activities of the catalysts. On the other hand, the comparison of catalytic activities of the prepared solid superacid catalysts and the conventional liquid acid H(2)SO(4) was also carried out under the same experimental conditions. The results show that the catalytic activities of the prepared solid superacid catalysts were higher than that of the conventional liquid acid H(2)SO(4), and that the catalytic activity of mesoporous TiO(2) solid superacid is the highest among the three catalysts. Mesoporous TiO(2) solid superacid is a good catalyst for the synthesis of isoamyl salicylate or cyclohexanone ethylene ketal.