超细Mo／Al2O3催化剂（I）：催化及还原性质研究

研究两种不同制方法－浸渍法和超临界流体干燥法制得的超细Ｍｏ／Ａｌ２Ｏ３催化剂的加氢与加氢脱硫催化性质及还原性质，并与以普通Ａｌ２Ｏ３作载体体制得的Ｍｏ／ＡｌＯ３催化剂相比较。结果表明，超细粒子催化剂催化性质较大度的地受制备方法的影响。ＴＰＲ，ＸＲＤ，ＬＲＳ分析结果表明，超细氧化铝载体和超临界流体干燥法的使用均有利于Ｍｏ在Ａｌ２Ｏ３表面的分散。     

新的聚合物支载硼氢负离子还原剂系统研究 3: 聚合物支载还原剂III

硼氢化钠的低分子还原系统研究很多,但其聚合物支载还原剂相对来说就很少,而且仅以强碱型阴离子交换树脂来制备的聚合物试剂。为了寻找用途更广泛的、新的聚合物支载还原剂,我们进行了硼氢负离子的聚合物还原系统的研究;发现能用弱酸型阳离子交换树脂制备出新的聚合物支载还原剂。前文报道了用NaBH_4的水溶液和阴离子交换树脂     

金负载量对低温水煤气变换Au/α-Fe2O3催化剂结构和性能的影响

采用共沉淀法制备了低温水煤气变换Au/α-Fe2O3催化剂。通过正交实验优化催化剂的还原活化条件，考察了金负载量对催化剂性能的影响。采用BET、XRD、UV-VIS、XRF、H2-TPR和O2-TPO等表征手段对催化剂的结构进行分析，并与其催化性能进行关联。结果表明，（1）采用10%-H2/N2还原气将催化剂在150 ℃原位还原9 h，其催化活性最高；（2）金的最佳负载量为8.00%，此时在催化剂制备过程中金的流失量较少，金粒子较小，也有利于抑制催化剂在反应过程中烧结；（3）TPR-TPO结果表明，金的负载量为8.00%时，Au/α-Fe2O3催化剂具有较易被还原、不易被氧化的性质，从而显示出最高催化活性。（4）Au/α-Fe2O3催化剂中的金以单质金（Au0）形式存在；其高活性与Au0-Fe3O4间的协同作用有关。     

F-T合成Fe/Cu/K/Al2O3催化剂的结构性质、还原及碳化行为

采用连续共沉淀与喷雾干燥成型技术相结合的方法制备了微球状Fe/Cu/K/Al2O3催化剂, 结合TG、N2物理吸附、XRD、H2-TPR、CO-TPR、Mossbauer谱等表征手段, 研究焙烧温度对Fischer-Tropshc (F-T)合成铁基催化剂的结构性质、还原行为和碳化行为的影响. 结果表明, 较高的焙烧温度有利于碳酸盐的分解和结晶水的脱除, 促进了催化剂的还原. 随着焙烧温度的进一步升高, 催化剂的比表面积减小, 平均孔径增大, α-Fe2O3晶粒的粒径增大, 催化剂中金属与载体的相互作用增强, 从而削弱了CuO、K2O助剂的作用, 严重抑制了催化剂的还原和碳化.     

铈锆比对低贵金属Pt＋Rh/Ce0.3＋xZr0.6－xY0.1O1.95＋Al2O3三效催化剂性能的影响

用共沉淀法制得一系列铈锆比不同的Ce_0.3＋xZr_0.6－xY_0.1O_1.95储氧材料, 并用于制备了一系列低贵金属Pt＋Rh/Ce_0.3＋xZr_0.6－xY_0.1O_1.95＋Al₂O₃三效催化剂. 用比表面、程序升温还原以及X射线衍射对该系列催化剂进行表征, 结果发现, 催化剂的活性与催化剂中贵金属的还原性能密切相关, 低铈储氧材料比高铈储氧材料更有利于促进贵金属还原, 因而含低铈储氧材料催化剂的活性明显优于含高铈储氧材料催化剂的活性, Pt＋Rh/Ce_0.35Zr_0.55Y_0.1O_1.95＋Al₂O₃的活性最佳, 对HC, CO和NO的起燃温度最低分别为: 235, 175, 200 ℃. 样品经1000 ℃水热老化之后, 贵金属Pt被烧结而发生迁移, 使得催化剂的活性及还原性能变差, 含低铈材料的催化剂的抗老化性能优于含高铈材料的催化剂, 其中Pt＋Rh/Ce_0.35Zr_0.55Y_0.1O_1.95＋Al₂O₃的抗老化性能最好.     

CVD Reactions of TiCl4 with Ammonia： a Quantum Chemical Study

Based on density functional calculations, the mechanism and the energetic course of the chemical vapor deposition （CVD） reaction of TiCl4 with NH3 were studied at the level of B3LYP with 6-311g（d） basis set. Furthermore, the polymerization processes of dimerization, trimerization and tetramerization were investigated. The calculation results indicate that the formation of polymers is favored at the elimination reaction. On the basis of the calculated energetics, a possible mechanism of the reduction reaction has been proposed.     

富氧条件下乙炔选择催化还原NOx

Acetylene as a reducing agent of metal exchanged HY catalysts, for selective catalytic reduction of NO in the reaction system of 0.16% NO, 0 （C2H2-SCR） was investigated over a series 08% C2H2, and 9.95% O2 （volume percent） in He. 75% of NO conversion to N2 with hydrocarbon efficiency about 1.5 was achieved over a Ce-HY catalyst around 300 ℃. The NO removal level was comparable with that of selective catalytic reduction of NOx by C3H6 reported in literatures, although only one third of the reducing agent in carbon moles was used in the C2H2-SCR of NO. The protons in zeolite were crucial to the C2H2-SCR of NO, and the performance of HY in the reaction was significantly promoted by cerium incorporation into the zeolite. NO2 was proposed to be the intermediate of NO reduction to N2, and the oxidation of NO to NO2 was rate-determining step of the C2H2-SCR of NO over Ce-HY. The suggestion was well supported by the results of the NO oxidation with O2, and the C2H2 consumption under the conditions in the presence or absence of NO.     

添加Ag对Cu／γ—Al2O3催化剂性能的影响

运用ＢＥＴ、ＸＲＤ、ＴＰＲ及苯和丙酮氧化活性测定等方面研究了Ｃｕ／γ－Ａｌ２Ｏ３和Ｃｕ－Ａｇ／γ－Ａｌ２Ｏ３催化剂的还原性能和有机物的催化活性，结果表明，不同金属负载量的Ｃｕ／γ－Ａｌ２Ｏ３催化剂的还原性能有明显差异，反映出催化剂表面存在着不同种类的铜物种，Ａｇ的添加使催化剂的ＴＰＲ峰位发生明显位移，提高了催化剂对有机物的催人活性，同时发现，热处理温度牟催伦剂中铜物种的存在形式、催化还原特性及催化     

还原气化—无色散原子荧光光谱法连测土壤样中痕量砷、锑、汞

应用氢化法—无色散原子荧光技术分析痕量As、Sb、Bi、Se、Te、Sn已有报导。     

Redox Polymerization of Methyl Methacrylate in the Fluorous Triphasic System

Fluorous-phase chemistry is currently a topic of considerable interest1-6. Since fluoroustriphasic reactions were first described by the Curran and co-workers7, this triphasicsystem has been widely used for detagging7,8 and phase-vanishing reactions9-11. …