The ZnO supported on -Al2O3, SiO2, MCM-41, and -zeolite were prepared and examined in the hydrogenation of methyl benzoate (MB). ZnO supported on -Al2O3 had a higher activity than ZnO. ZnO/-Al2O3 modified with 23 ppm lithium had a high catalytic activity (97%) and high selectivity to benzaldehyde (BD, 87%) in a fixed-bed reactor at atmospheric pressure and 400℃. Chromium oxide modified ZnO/ -Al2O3 also had a high selectivity to BD. Hydrogenolysis of MB occurred over copper modified catalysts. X-ray powder diffraction (XRD) revealed that in the ZnO/-Al2O3 catalysts, the ZnO, ZnAl2O4 and -Al2O3 phases exited mainly, the border of ZnO and ZnAl2O4 might be important for the hydrogenation of MB to BD. XPS and FT-IR revealed that the chemical environment of ZnO on the ZnO/-Al2O3 catalyst is different to ZnO and other supported ZnO catalysts, which gives the ZnO/-Al2O3 catalyst having a higher activity than ZnO or ZnO on SiO2, MCM-41 or -zeolite. The presence of third metal (Li, Cr or Cu) oxide in ZnO/-Al2O3 could change the electronic structure of Zn and the chemical phenomena of Zn-Al in catalyst and lead to change of the catalytic performance.

As a novel support of immobilizing penicillin G acylase (PGA), MCM-48 and Co-MCM-48 molecular sieves were synthesized and characterized by XRD, N2 adsorption, NH3-TPD, FT-IR and so on. The studies show that MCM-48 and Co-MCM-48 has well ordered long-range structure, narrow pore size distribution, larger surface area and higher concentration of the weakly acidic silanol groups on their surface. PenicillinGacylasewas immobilized on MCM-48 or Co-MCM-48 by interacting silanol groups on the surface. The presence of cobalt in the framework of MCM-48 increases the amount of the weak acid sites. For the hydrolysis of penicillin G catalyzed by PGA/Co-MCM-48 (Co/Si=0.01), its specific activity reaches 1682U/g. After used for six cycles, PGA/MCM-48(0.01) can keep 1375U/g of the specific activity. If MCM-41 was used as the support, the activity of immobilized PGA is only 402U/g.

The TS-1/diatomite catalyst was prepared for the hydroxylation of phenol with H2O2 in the fixed-bed reactor and the effects of pretreatment on the properties of TS-1/diatomite were studied by FT-IR, XRD, UV-vis, ICP-AES, BET surface area and NH3-TPD techniques. It is shown when the catalyst is pretreated by the KAc, NaAc, NH4Ac, NH4Cl or HNO3 aqueous solution, the framework structure of TS-1 is not destroyed and titanium in the framework is not removed. The surface area of catalyst has no obvious change compared with that of the untreated catalyst. But the extra-framework TiO2 can be removed partly, which leads to the slight increase of the crystallinity of catalyst and the decrease of acid concentration on the surface of the TS-1/diatomite catalyst. As a result, the activity, selectivity and utilization of H2O2 for hydroxylation of phenol are improved. After the TS-1/diatomite catalyst is pretreated by the NH3•H2O, Na2CO3 or Na3PO4 solution, its framework silicon is dissolved partly in the base solution and the framework structure of TS-1 is destroyed. While the crystallinity and surface area of catalyst decrease and the concentration of acid sites on the surface of catalyst increased slightly. As a result, the catalytic activity of the TS-1/diatomite catalyst for hydroxylation of phenol descended or deactivated completely.

Direct gas-phase epoxidation of propylene to propylene oxide (PO) by molecular oxygen was studied over the MoO3-modified supportedsilver catalyst. The effect of promoter and support on the performance of the Ag-MoO3 catalyst and their role were investigated by XPS, XRD, SEM, BET surface area, NH3-TPD, CO2-TPD techniques and so on. As the promoter, MoO3 plays a great role of electron- and structure-type bi-functional promoter. Of all the supports studied, ZrO2 is the most suitable one for the Ag-MoO3 catalyst. The presence of support can regulate the size of the Ag-MoO3 particles and the pore radii of catalyst, and decrease the loading of MoO3 from ∼50wt.% in the unsupported Ag-MoO3 catalyst to ∼4wt.% in the Ag-MoO3/ZrO2 catalyst. The properly weak Lewis acidic sites, the larger size of the Ag-MoO3 particles and pore channel on the Ag-MoO3/ZrO2 catalyst are beneficial to improve epoxidation performance of the catalyst. The effect of the reaction temperature and space velocity on the catalytic epoxidation of propylene was also investigated. The low temperature or high space velocity can decrease the deep oxidation of propylene oxide to improve the selectivity to PO. Over the 20%Ag-4%MoO3/ZrO2 catalyst at 400℃, 0.1MPa and space velocity of 7500h−1, the selectivity to PO of 60.3% was achieved with the O2 conversion of 4.8%; under the space velocity of 12 000h−1, the selectivity to PO was 71.5% with 2.5% O2 conversion.

A series of supported ZnO catalysts were prepared by a novel method, hydrothermal-impregnation-precipitation (HIP). The activities of catalysts were tested for hydrogenation of methyl benzoate (MB). ZnO supported on MCM-41 behaves much higher activity than that on -Al2O3, -zeolite and SiO2. Changing the loading of ZnO on MCM-41 can adjust the depth of hydrogenation of MB, and high loading of ZnO is available for the hydrogenolysis of MB to benzene. XRD, FT-IR and N2 absorption were used to reveal that zinc oxide incorporated into the pore channels of MCM-41 in single or double molecular ZnO layer. After supporting 10%ZnO on MCM-41 by HIP, the structure of MCM-41 is unchanged, its pore diameter decreases from 3.14 to 2.62nm.