Nanoparticles of the CeO2-ZrO2-La2O3 solid solution were prepared by the W/O microemulsion method. Ceria-zirconia-lanthana (Ce/Zr/La=1/1/0.06,mol) sample calcined at 1000 for 4h has higher surface area (126m2/g) and excellent thermal stability. Its particle size is 5-10nm. The presence of lanthana in the sample can improve obviously the thermal stability of the CeO2-ZrO2 solid solution.

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 effects of calcination temperature and preparation method of TiO2-ZrO2 mixed oxide on catalytic performance of B2O3/TiO2-ZrO2 catalysts were investigated. TiO2-ZrO2 mixed oxides with the same molar ratio of 1:1 were prepared by co-precipitation method, homogeneous precipitation method, sol-gel method and physical mixing method; each oxidewas calcined at a temperature between 110 and 700℃. Catalytic synthesis of ε-caprolactam from cyclohexanone oxime was evaluated in a fixed-bed flow microreactor at 300℃ and atmosphere pressure. Characterization of catalysts was carried out using adsorption of nitrogen, X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR) and temperature-programmed desorption of ammonia (NH3-TPD) techniques. The experimental results reveal that the calcination temperature in the range of 110-500℃ had only a slight effect on the catalytic performance, but after calcination at 700℃, the ZrTiO4 crystallite was formed and accounted for the decrease of acidity and catalytic performance. The co-precipitation method provided the catalyst with the highest reactivity while the physical mixing method resulted in the worst catalyst. Catalytic performance of the B2O3/TiO2-ZrO2 catalyst was closely related to its acid strength distributions and pore size.

Pure TiO2, ZrO2 and TiO2-ZrO2 mixed oxides with various compositions were prepared by the co-precipitation method. Catalysts containing 12wt.% boria were prepared using these oxides and their catalytic performance for vapor-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam was determined.With increasing zirconia content in the mixed oxide, the specific surface area and the temperature of the phase transformation increased; maximum values were obtained for a mixed oxide having a Ti and Zr molar ratio of 1/1. XRD results indicated that TiO2-ZrO2 became amorphous after calcination at 500℃ if neither the content of TiO2 nor that of ZrO2 was less than 25%. The yield of lactam increased with increasing zirconia content in mixed oxide and reached a maximum value for the B2O3/TiO2-ZrO2 (1/1) catalyst.With further increase in zirconia content, the lactam yield decreased; the lowest value was observed for the pure ZrO2-supported catalyst. The acidic property and the pore characteristics of the catalyst were key factors that affected its performance. The influences of the operating parameters on the performance of B2O3/TiO2-ZrO2 (1/1) catalyst were also investigated.

Monte Carlo simulations were used to search for the optimal probability estimator for estimating Weibull parameters with the linear regression method. Compared with commonly used probability estimators, the optimal one obtained gives a more accurate estimation of the Weibull modulus and the same estimation precision of the scale parameter. It is also concluded that the maximum likelihood method results in the highest precision, however, less conservative than the linear regression method.