硫酸锌水合物催化合成癸二酸二丁酯的研究

以硫酸锌水合物为催化剂催化合成癸二酸二丁酯 ,确定了酯化优化条件。试验结果表明 :在催化剂 2 .5g,癸二酸 0 .0 5 mol,丁醇 0 .3m o L,反应时间 90 min的条件下 ,癸二酸的酯化率 96 .5 %。

Biotransformation of Gastrodin by Mucor spinosus

Microbial transformation of gastrodin by Mucor spinosus strain 3.3450, resulted in a product with a transformation rate close to 100 per cent. This product was identified as p-hydroxy benzyl alcohol on the basis of its 1H, 13C NMR and EI-MS spectral data. It could be inferred that the enzyme responsible for the biotransforma-tion reaction was a kind of extracellular and constitutive enzyme since the transformation reaction of the substrate could be carried out in cell free extracts of the fermentation broth of the Mucor spinosus.

Study on Methanol Oxidation at Pt and PtRu Electrodes by Combining in situ Infrared Spectroscopy and Differential Electrochemical Mass Spectrometry

Methanol oxidation reaction （MOR） at Pt and Pt electrode surface deposited with various amounts of Ru （denoted as PtxRuy, nominal coverage y is 0.17, 0.27, and 0.44 ML） in 0.1 mol/L HClO4＋0.5 mol/L MeOH has been studied under potentiostatic conditions by in situ FTIR spectroscopy in attenuated-total-reflection con guration and di erential electro-chemical mass spectrometry under controlled flow conditions. Results reveal that （i） CO is the only methanol-related adsorbate observed by IR spectroscopy at all the Pt and PtRu electrodes examined at potentials from 0.3 V to 0.6 V （vs. RHE）; （ii） at Pt0.56Ru0.44, two IR bands, one from CO adsorbed at Ru islands and the other from COL at Pt substrate are detected, while at other electrodes, only a single band for COL adsorbed at Pt is observed; （iii） MOR activity decreases in the order of Pt0.73Ru0.27〉Pt0.56Ru0.44〉Pt0.83Ru0.17〉Pt; （iv） at 0.5 V, MOR at Pt0.73Ru0.27 reaches a current e ciency of 50% for CO2 production, the turn-over frequency from CH3OH to CO2 is ca. 0.1 molecule/（site sec）. Suggestions for further improving of PtRu catalysts for MOR are provided.

Effects of Ppc Gene Construction of Monocotyledon on Seedling Growth of Transgenic Nicotiana tabacum

To compare the transformation effects of two different forms （cDNA in monocotyledonous plant Echinochloa crusgalli, DNA in monocotyledonous plant Zea mays） of phosphoenolpyruvate carboxylase （PEPC） gene （Ppc） on the growth of transgenic dicotyledonous plant, Agrobacterium-mediated transformation of Ppc genes into Nicotiana tabacum were carried out. Transgenic leaf plates and differentiated seedling leaves were verified by GUS histochemistry, PCR, and RT-PCR. Results showed that transgenic N. tabacum with Ppc-cDNA of E. crusgalli had relatively strong differentiation ability. However, N. tabacum after transformation of complete DNA sequence of Ppc genes in Z mays had relatively poor ability of growth. The differentiated green seedlings had the phenomenon of yellowing; and photosynthesis ability of leaves was poor. This might be caused by the misidentification and wrong splicing in transcription. This indicated that the expression rate of monocotyledonous complete DNA might be reduced in the monocotyledonous cells with relatively far genetic distances. Detection results of showed that Pn in most transgenic N. tabacum with Ppc-cDNA of E. crusgalli was was higher than that in control, which preliminarily proved that PEPC of monocotyledonous plant E. crusgalli had certain regulatory effects on photosynthesis of N. tabacum.

Kinetics of esterification of methanol and acetic acid with mineral homogeneous acid catalyst

In this work, esterification of acetic acid and methanol to synthesize methyl acetate in a batch stirred reactor is studied in the temperature range of 305.15–333.15 K. Sulfuric acid is used as the homogeneous catalyst with concentrations ranging from 0.0633 mol·L-1to 0.3268 mol·L-1. The feed molar ratio of acetic acid to methanol is varied from 1:1 to 1:4. The influences of temperature, catalyst concentration and reactant concentration on the reaction rate are investigated. A second order kinetic rate equation is used to correlate the experimental data. The forward and backward reaction rate constants and activation energies are determined from the Arrhenius plot.The developed kinetic model is compared with the models in literature. The developed kinetic equation is useful for the simulation of reactive distillation column for the synthesis of methyl acetate.

Modeling and Optimization of Catalytic Dehydration of Ethanol to Ethylene Using Central Composite Design

The central composite design in the modeling and optimization of catalytic dehydration of ethanol to ethylene was performed to improve the ethylene yield.A total of 20 experiments at random were conducted to investigate the effect of reaction temperature,Si/Al ratios of H-ZSM-5 catalyst and liquid hourly space velocity(LHSV) on the ethylene yield.The results show that the relationship between ethylene yield and the three significant independent variables can be approximated by a nonlinear polynomial model,with R-squared of 99.9%and adjusted R-squared of 99.8%.The maximal response for ethylene yield is 93.4%under the optimal condition of 328 ℃,Si/Al ratio 85,and LHSV 3.8 h-1.

Measurements of Conductivity for Low Concentration Strong-electrolytes in Organic Solvents (Ⅰ) LiBr, LiCl, and LiNO_3 in Alcohols

The conductivities of LiBr, LiCl, and LiNO 3 in methanol, ethanol, 1-propanol, and 2-propanol (with electrolyte concentrations <0.08 mol·L-1 ) were determined at 298.15 K, 313.15 K, and 323.15 K at atmosphere pressure separately by using a conductivity meter. The conductivity data were correlated with Foss-Chen-Justice (FCJ) equation and the limiting molar conductivities were obtained. The mean ionic activity coefficients of the salts in the organic solvents were calculated according to the Debye-Hückel limiting law and Onsager-Falkenhangen equations. The calculated results were compared with those activity coefficients in literature.

A comparative study of the electrooxidation of C1 to C3 aliphatic alcohols on Ni modified graphite electrode

Nickel modified graphite electrodes （G/Ni） prepared by galvanostatic deposition were examined for their redox process and electrocatalytic activities towards the oxidation of methanol, ethanol, 1-propanol and 2-propanol in alkaline solutions. The methods of cyclic voltammetry （CV）, ehronoamperometry （CA） and impedance spectroscopy （EIS） were employed. In CV studies, the electrochemical response, peak current varied in the order of MeOH 〉 EtOH 〉 1-PrOH 〉 2-PrOH. Under the CA regime, a higher catalytic rate constant obtained for methanol oxidation was in agreement with CV measurements. Lower charge transfer resistance was obtained for low carbon alcohols oxidation and significantly higher exchange current density was obtained for methanol oxidation.

Acceleration of disproportionation reactions of aryl alcohols in water medium by CO_2

Compressed CO~ could promote the disproportionation reactions of aryl alcohols in water medium significantly. The control experiments indicated that the effect of CO2 on the properties of the reactant/water emulsions was the main reason for the ac- celeration of the reactions rate.