Syntheses of TiO2 photocatalysts by the molten salts method: Application to the photocatalytic degradation of Prosulfuron

Titania photocatalysts were synthesised by the molten salts method by reaction of a titanium precursor with three different alkali metal nitrates (LiNO₃, NaNO₃, KNO₃). The titania powders obtained have been characterised using TEM, XRD, BET and UV-Vis absorption spectroscopy. Their photoactivities were evaluated by degrading a commercial sulfonylurea herbicide, Prosulfuron^®. It has been found that the rate constants increased in the following order: Li2 prepared in KNO₃, with a rate constant 1.4 times smaller than that of P25. The effect of calcination was also studied, especially for the sample prepared in NaNO₃ (TiO₂[Na]). An improvement in photocatalytic activity was observed when TiO₂[Na] was calcined in the region of 700–800 °C. Even though the photocatalytic activities obtained did not exceed or even equal to that of Degussa P25, nevertheless, this study constitutes the first attempt to synthesise titania photocatalysts by the molten salts method.     

用D_2EHPA-煤油溶剂萃取分离L-异亮氨酸

本文研究了从发酵液中用D2EHPA－煤油溶剂萃取分离L－异亮氨酸工艺．考察了萃取时pH值、萃取剂浓度和异亮氨酸浓度对于异亮氨酸和缬氨酸的萃取分配比的影响．在计算机上进行回归，得到以下分配模型：当1≤pH≤3．5时lgDIle＝0．09906pH2＋0．8625pH＋2．2696lgCHR－0．09188lg2CIle＋0．1766lgCIle－1．366lgDrmVal＝－0．0293pH2＋0．550pH＋1．2659lgCHR－0．2420lg2CIle＋0．4549lgCIle－1．696用此模型，应用分馏萃取理论，进行逐级计算，求取了萃取工艺的主要参数，并在φ20mm的多级离心萃取器上对上述结果进行了验证．结果表明：当CHR浓度为1．5mol／L，相比V：L：L’＝2：1：2，N’＝3，N＝6时，异亮氨酸的收率达到90％以上，纯度＞99％．实验取得了较为满意的结果．     

强酸性阳离子交换树脂催化合成氯乙酸异辛酯的研究

对采用７３２强酸性苯乙烯系阳离子交换树脂作催化剂合成氯乙酸异辛酯进行了实验研究，提出了适宜的反应条件。实验结果表明，该法酯化率高、过程简便、产物颜色浅，优于浓硫酸作催化剂。     

金属离子掺杂二氧化钛及水体光催化脱氮研究

采用溶胶-凝胶法制备了掺杂Ce^3＋、La^3＋、Ag^＋、Fe^3＋的TiO2光催化剂，以考察其薄膜和粉体形式对水中无机氮的光催化去除效果和活性．用所制备的催化剂对含氨氮-亚硝酸氮的混合液进行了光催化脱氮研究．本文利用UV—Vis吸收光谱、XRD和TEM对催化剂进行了表征．同时，对影响TiO2光催化效率的因素：如掺杂金属离子的种类、浓度、涂膜层数、反应液中有无Fe^2＋、不锈钢和玻璃载体、反应器的构型等进行了探讨，并对今后的研究进行展望．经过2h紫外光照射反应，实验最佳脱氮效果：金属离子掺杂TiO2薄膜型催化剂总氮去除率在30％左右，金属离子掺杂粉末型催化剂光催化最高总氮去除率可达41．7％．     

核壳型二氧化钛复合纳米材料研究进展

核壳材料由中心核和外部壳层组成，因其组成、大小、结构的不同，性能优于普通材料。二氧化钛具有优异的光、电和化学等特性可作为理想的核壳材料。从二氧化钛作为核壳型复合纳米材料的核、壳及核壳结构的载体3个方面出发，介绍了核壳型结构的二氧化钛复合纳米材料的分类、制备、性质及应用概况，并对其发展前景及存在问题进行了简要概述。     

Chemistry of hydrogen sulphide under coal liquefaction conditions: 1. Modelling hydrogen transfer catalysis

The work reported here represents initial attempts to develop a complete kinetic and mechanistic understanding of the reaction chemistry of H₂S under coal liquefaction conditions, using both model systems and coal. Hydrogen sulphide was found to promote/catalyse the transfer of hydrogen from tetralin to 2-hydroxyquinoline (2-HOQ). The presence of H₂S can increase the rate of hydrogen transfer from tetralin to 2-HOQ by a factor of 10 compared with the same reaction run in the absence of H₂S. The energy of activation for hydrogen transfer was found to decrease by ≈5 kcal mol⁻¹ in the presence of H₂S. The presence of H₂S was also found to promote loss of oxygen from 2-HOQ to form small amounts of quinoline. No evidence of CC or CN bond cleavage in 2-HOQ was noted under any of the reaction conditions studied. These results suggest that the presence of H₂S reduces the temperatures necessary to promote effective hydrogen transfer from tetralin by 50–75 °C. Moreover, they imply that similar effects occur in H₂S-promoted coal liquefaction.     

甲基-酰基-萘在庚烷、辛烷和十二烷中溶解度的测定与关联

The solubilities of 2-methyl-6-acetylnaphthalene (2,6-MAN) and 2-methyl-7-acetylnaphthalene (2,7-MAN) in n-heptane, n-octane, and n-dodecane were measured, respectively, from 273.15 to 319.15 K using an analytical method. On the basis of the thermodynamics theory of solid-liquid equilibrium, a model was derived to relate the solubilities with temperature. Using the least square method, the parameters of the model, the fusion enthalpies △fusH and the Margules equation coefficients A12 and A21 of 2,6-MAN and 2,7-MAN in n-heptane, n-octane, and n-dodecane-were obtained by regressing the experimental data. The average deviation of the model was 1.70%.     

云母钛珠光颜料的研究

综述了云母钛珠光颜料的发展概况，介绍了它的三种类型：银白色型、虹彩型、着色型，着重论述了它的生产工艺和制备方法(气相包覆法和液相沉积法)，并比较了各类方法的优缺点，分析了它的晶型类别(板钛型、锐钛型、金红石型)、包膜的复合机理和虹彩效应形成的原因，并指出国内产品的发展方向。     

Investigation of bio-ethanol steam reforming over cobalt-based catalysts

The catalytic performance of cobalt catalysts supported on γ-Al₂O₃, TiO₂, ZrO₂ were studied for bio-ethanol steam reforming (BESR) reaction. The supported catalysts (10 wt%Co) were prepared by impregnation and characterized through Thermogravimetric analysis (TGA), H₂ chemisorption, laser Raman Spectroscopy, Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), and temperature-programmed reaction (TPRxn). The metallic cobalt sites were found to correlate with the BESR reaction activity. The reaction and H₂ chemisorption showed that ZrO₂ supported catalyst showed the best dispersion and best catalytic activity. Over the 10% Co/ZrO₂ catalyst, using a H₂O:EtOH:inert molar ratio of 10:1:75 and a GHSV = 5000 h⁻¹, 100% ethanol conversion and a yield of 5.5 mol H₂/mol EtOH were obtained at 550 °C and atmospheric pressure.     

阳离子香豆胶的合成及结构表征

以3-氯-2-羟丙基三甲基氯化铵(HAT)为阳离子醚化剂,天然香豆胶为原料,异丙醇为分散剂制得季铵盐型阳离子香豆胶。研究了HAT、催化剂NaOH、反应温度和反应时间对合成阳离子香豆胶(CFG)的影响,用凯氏定氮法测定了CFG的取代度。合成CFG的优化实验条件为:m(香豆胶)∶m(异丙醇)∶m(HAT)∶m(NaOH)=1∶(1.6~2)∶(0.15~0.3)(∶4~8),反应温度40~50℃,反应时间2~3 h,制得的产品能满足工业应用要求的黏度及取代度范围(500~800 mPa.s,DS=0.86~1.32)。用FTIR和13CNMR对CFG的结构进行了表征。