纳米材料负载钌催化剂的制备与应用
摘要：钌基催化剂在温和条件下具有优异的催化性能,因而广泛应用于各种反应中.主要综述了纳米材料负载钌催化剂的制备方法和应用研究的最新进展,总结了载体材料、前驱体和纳米钌粒子对催化剂性能的影响,系统地介绍负载型钌催化剂最新制备方法和传统制备方法的新发展,并简单探讨了各种方法的优缺点,较全面地概述了负载型钌催化剂的应用领域及其性能,展望了其发展前景.磷脂对脂肪酶催化性能的影响
摘要：脂肪酶催化可再生动植物油脂的酰基化反应可以生产多种具有重要价值的化工产品,近年来受到了越来越多的关注.而天然油脂原料中往往含有一定量的磷脂,它对脂肪酶的催化活性、热稳定性以及反应动力学等的影响非常显著.介绍了油脂中存在磷脂的种类与结构,并分别针对脂肪酶催化的水解、酯化和转酯化反应过程,综述了磷脂对脂肪酶催化性能的影响,以及可能的作用机制.室温MnO_x上O_3氧化脱除空气中甲醛
摘要：采用氧化还原法制备了MnOx催化剂,X射线衍射结果表明其主要为无定形结构.在甲醛和臭氧浓度分别为137和642mg/m3,相对湿度为56%（25oC）,GHSV为2×105h-1条件下,MnOx催化剂上O3可将甲醛全部氧化为CO2,反应150min内甲醛转化率和CO2选择性一直保持在～100%.另外,当臭氧与甲醛的摩尔比约为2：3,即显著低于化学计量比时,CO2选择性仍可达～100%.采用傅里叶变换红外光谱仪在线分析了甲醛氧化反应产物,未检测到任何副产物,从而确认了MnOx催化剂上O3对甲醛的完全氧化.温控离子液体/有机两相体系中纳米Rh催化烯烃氢甲酰化反应
摘要：将具有＂高温混溶、室温分相＂功能的离子液体[CH3（OCH2CH2）16N＋Et3][CH3SO3–]（ILPEG750）与甲苯-正庚烷组成的两相体系用于纳米Rh催化的烯烃氢甲酰化反应中,在优化的反应条件下,1-辛烯转化率和醛收率分别为99%和91%.催化剂经简单分相即可与产物分离,且可连续使用8次,其活性基本保持不变.Au（111）表面上乙醇选择性氧化反应机理的密度泛函理论研究（英文）
摘要：采用密度泛函理论研究了吸附有O原子的Au（111）表面上乙醇选择性氧化的反应机理.反应结果表明,除O原子和中间产物二齿醋酸根（CH3CHOO）外,其他中间产物在Au（111）表面扩散能垒均较低,不会对反应速控步骤的确定造成影响.乙醇羟基氧化脱氢为反应的第一步骤,当氧化剂为吸附态的O原子或者为OH基时,反应活化能分别为0.20和0.17eV.氧化产物乙氧基（CH3CH2O）进一步氧化脱氢生成乙醛则需要表面吸附的O原子或另一表面吸附的OH基的参与,所需活化能为0.29或0.27eV.同时,乙醛易与表面吸附的乙氧基反应生成乙氧基半缩醛（CH3CHOOC2H5）,其可进一步与O原子作用,脱氢形成乙酸乙酯.此外,在乙醛深度氧化成酸的过程中需要克服较高的反应能垒,因而在表面反应温度较低时无法进行,这与实验结果相符.无机氧化物载体对催化CO_2与环氧化合物合成环状碳酸酯的促进作用（英文）
摘要：以一系列无机氧化物与四丁基溴化铵为双组分催化剂体系,考察了其催化CO2和环氧化合物合成环状碳酸酯的反应性能.结果表明,在四丁基溴化铵与这些本身并没有催化活性的无机氧化物共同作用下,反应活性明显提高,表现出很强的协同催化作用.另外,通过对SiO2的表面硅烷基化,考察了其表面羟基数量对反应活性的影响,发现当SiO2的表面经过硅烷基化以后,反应活性大幅度降低,表明无机氧化物表面羟基对CO2环加成反应活性有非常显著的促进作用.La_2O_3对CuO/CeO_2水煤气变换反应催化剂微观结构及催化性能的影响（英文）
摘要：以La2O3为助剂,采用共沉淀法制备了具有良好催化活性和热稳定性的CuO/CeO2-La2O3水煤气变换反应催化剂,其中,当La2O3含量为2wt%时,催化剂的催化性能最为优异.同时运用X射线衍射、N2吸附-脱附、Raman光谱、程序升温还原等手段,研究了不同含量的La2O3对CuO/CeO2催化剂微观结构及催化性能的影响.结果表明,La2O3助剂进入了载体CeO2的晶格并对CuO/CeO2催化剂的微观结构和催化性能产生了直接影响,适量La2O3的添加可以抑制CuO和CeO2晶格的长大、增强CuO与CeO2间的相互作用、提高催化剂的比表面积、促进CeO2载体中生成更多的氧空位,CuO/CeO2催化剂的催化活性和热稳定性也明显改善.脂肪酶催化缩聚法合成可完全降解的聚羟基丙酸酯（英文）
摘要：以3-羟基丙酸甲酯为聚合单体,建立了以固定化脂肪酶Novozym 435为催化剂的酶催化缩聚反应体系,合成可完全降解的高分子聚酯聚羟基丙酸酯,考察了反应条件和介质对反应性能的影响,结果表明,纯度大于95%的单体即可在温和条件下合成聚羟基羧酸酯;降低反应压力可有效提升产物产率和分子量.通过选择合适的有机溶剂介质和表面活性剂,可使产物分子量提升至13000（Mw）以上.脂肪酶催化剂重复利用能力优异,经6批次反应后,其相对活性保持在95%以上.Synthesis of 2-Substituted Benzimidazoles and 1,5-Disubstituted Benzodiazepines on Alumina and Zirconia Catalysts
摘要：In this study, alumina, zirconia, manganese oxide/alumina, and manganese oxide/zirconia have been investigated for their catalytic activity in the condensation reaction between o-phenylenediamine and an aldehyde or a ketone to synthesise 2-substituted benzimidazoles and 1,5-disubstituted benzodiazepines respectively. Surface area, surface acidity, and morphology of the catalysts have been analysed and correlated with their catalytic activity. The isolated yields of 2-substituted benzimidazoles and 1,5-disubstituted benzodiazepines are in the range of 30% to 95%. A good correlation between the amount of surface acid sites as well as the surface morphology of the catalysts and the catalytic activity has been observed. This method has been found to be simple and economical. The solid supports could be regenerated and reused without much loss in their activity. Further, the solid supports have been also found to be effective as general catalysts in the condensation of o-phenylenediamine with other substituted aldehydes and ketones.MgO/h-BN复合载体对Ba-Ru/MgO/h-BN氨合成催化剂性能的影响（英文）
摘要：采用浸渍法制备了系列不同质量比的MgO/h-BN复合载体负载的Ru基氨合成催化剂,采用X射线衍射、N2低温物理吸附、X射线荧光、扫描电镜、透射电镜、程序升温分析等手段对催化剂进行了详细的表征,并在固定床反应器上考察了它们在氨合成反应中的催化性能.结果表明,MgO/h-BN复合载体中h-BN含量对催化剂活性的影响较大,Ba-Ru[1：1]（摩尔比）/MgO/h-BN[8：2]（质量比）,Ba-Ru[1：1]/MgO/h-BN[6：4]和Ba-Ru[1：1]/MgO/h-BN[5：5]催化剂上氨合成活性均高于Ba-Ru/MgO催化剂.在425°C,5.0MPa,N2/H2=1/3和5000h？1条件下,Ba-Ru[1：1]/MgO/h-BN[8：2]表现出最优催化活性,达506.9ml/（gcat·h）.这可归因于MgO/h-BN复合载体上存在较高数量的碱性位,特别是弱碱性位和中等强度碱性位,而这些碱性位可能是由MgO和h-BN之间的相互作用造成.水热老化对不同方法制备的Fe-ZSM-5用于NH_3选择性催化还原NO_x的影响
摘要：采用液体离子交换、等体积浸渍和固相离子交换制备了一系列Fe-ZSM-5催化剂,并将其用于NH3选择性催化还原NOx（NH3-SCR）反应.运用X射线衍射、紫外-可见漫反射吸收光谱和原位漫反射傅里叶变换红外光谱对催化剂进行了表征.结果表明,Fe-ZSM-5催化剂表面Fe物种可分为孤立Fe3＋物种、低聚Fe氧化物团簇和Fe2O3,各催化剂上NH3-SCR反应活性不同的根本原因是其表面Fe物种分布不同.水热老化后,Fe-ZSM-5催化剂上400oC以下反应时NOx转化率降低,而高温活性略有提高,各催化剂活性差异减小;同时NH3氧化活性和NO氧化活性均明显降低.这可归因于水热老化使Fe-ZSM-5催化剂表面的孤立Fe3＋物种相对浓度降低,低聚Fe氧化物团簇和Fe2O3相对浓度增加,以及催化剂表面Br？nsted酸性位显著减少所致.以原位形成的磷酸铝骨架为模板制备纳米孔炭（英文）
摘要：以不同有机物（邻苯二酚、间苯二酚、对苯二酚、乙二醇、环己胺）为辅助炭源,通过直接炭化含柠檬酸及磷酸铝的复合物制备了一系列纳米孔炭材料（NC）,采用多种表征手段研究了辅助炭源对最终炭材料性质的影响.结果表明,NC材料的结构和表面官能团性质随辅助炭源的变化而改变,其中以间苯二酚、对苯二酚、环己胺为辅助炭源制备的炭材料在空气氧化苯甲醇反应中表现有较高的催化活性.聚甲基丙烯酸羟乙酯负载手性Mn（III）salen配合物催化α-甲基苯乙烯的不对称环氧化反应（英文）
摘要：在手性Mn（III）salenCl配合物的5和5＇位上引入氨基醇,将其通过轴配位作用负载于聚甲基丙烯酸羟乙酯（pHEMA）上,并用于离子液体[bmim]PF6中,催化α-甲基苯乙烯的不对称环氧化反应.结果表明,该催化剂表现出良好的催化活性和区域选择性,对映体过量值（ee）和产率可分别达80%～91%和84%～92%,循环使用5次后催化活性没有明显降低.这可归结为氨基醇和环己二胺中手性碳原子间相互协同作用.Catalytic Performance of Al-MCM-48 Molecular Sieves for Isopropylation of Phenol with Isopropyl Acetate
摘要：Al-MCM-48 molecular sieves （Si/Al molar ratios = 25, 50, 75, and 100） were synthesized hydrothermally using cetyltrimethyl-ammonium bromide as the structure directing template. The orderly arrangement of mesopores was evident from the low angle X-ray diffraction patterns and transmission electron microscopy images. The catalytic performance of the materials was evaluated in the vapor phase isopropylation of phenol with isopropyl acetate. Phenol conversion decreased with the increase in the Si/Al ratio of the catalysts. The major reaction product was 4-isopropyl phenol with 78% selectivity. The delocalization of phenolic oxygen electron pair over the aromatic ring promoted para-selective alkylation. Such delocalization could be aided by the hydrophilic surface of the molecular sieves. Although an ester was used as the alkylating agent, phenyl isopropyl ether was not formed in the reaction.New Modified-Multiwall Carbon Nanotubes Paste Electrode for Electrocatalytic Oxidation and Determination of Hydrazine Using Square Wave Voltammetry
摘要：The application of p-aminophenol as a suitable mediator, as a sensitive and selective voltammetric sensor for the determination of hydrazine using square wave voltammetric method were described. The modified multiwall carbon nanotubes paste electrode exhibited a good electrocatalytic activity for the oxidation of hydrazine at pH = 7.0. The catalytic oxidation peak currents showed a linear dependence of the peaks current to the hydrazine concentrations in the range of 0.5–175 μmol/L with a correlation coefficient of 0.9975. The detection limit （S/N = 3） was estimated to be 0.3 μmol/L of hydrazine. The relative standard deviations for 0.7 and 5.0 μmol/L hydrazine were 1.7 and 1.1%, respectively. The modified electrode showed good sensitivity and selectivity. The diffusion coefficient （D = 9.5 × 10–4 cm2/s） and the kinetic parameters such as the electron transfer coefficient （α = 0.7） of hydrazine at the surface of the modified electrode were determined using electrochemical approaches. The electrode was successfully applied for the determination of hydrazine in real samples with satisfactory results.二氧化硅担载Preyssler杂多酸上苯和1-癸烯的烷基化反应：利用表面响应方法进行统计设计（英文）
摘要：The response surface method （RSM） was applied to study the liquid phase alkylation of benzene with 1-decene catalyzed by means of silica supported Preyssler heteropoly acid. A three step experimental design was developed based on the central composite design （CCD）. Catalyst loading, catalyst mass percent, and benzene to 1-decene molar ratio were used to optimize 1-decene conversion and linear alkylbenzene （LAB） yield. The results indicated that the quadratic model was significant for these two responses. The experimental results revealed that all variables had positive effect on 1-decene conversion. While increasing the catalyst loading tends to decrease LAB yield. Benzene to 1-decene molar ratio was found to be the most important factor that influenced LAB yield with a positive effect. Design expert software suggested several optimized solutions, among them the best choice was to use 31% catalyst loading, benzene to 1-decene molar ratio of 13, and catalyst percent of 3.6 wt% for obtaining 100% conversion and 88% LAB production yield.咪唑（啉）-2-羧酸盐作为潜在的/可热活化的有机小分子催化剂催化转酯反应（英文）
摘要：采用咪唑（啉）-2-羧酸盐（ImCO2）作为催化剂前驱体,通过温度控制脱除ImCO2的2-位羧酸根,再原位释放出高活性的N-杂环卡宾（NHCs）,进而催化转酯反应.研究了NHCs在苯甲酸乙酯与一元醇、二元醇及氨基醇反应体系中的催化活性.结果表明,在该体系中不需要选用活化酯为原料,无需加入分子筛或加大醇酯比提高产率,仅用少量催化剂（0.5mol%）,在较短时间内（3h）,即可使反应转化率达到95%.磷化镍/介孔TiO_2催化剂的制备及其催化加氢脱硫性能
摘要：以介孔TiO2（m-TiO2）为载体,采用程序升温还原法制备了Ni2P/m-TiO2催化剂,考察了不同起始Ni/P摩尔比及活性组分负载量对该催化剂结构及其催化加氢脱硫（HDS）性能的影响.结果表明,当Ni/P摩尔比为1.25时,活性组分以Ni2P为主,催化剂的最佳Ni负载量为10%.采用X射线衍射、低温N2吸附-脱附、场发射扫描电镜和程序升温还原等技术表征了m-TiO2及其它不同载体负载的Ni2P催化剂.结果表明,高结晶度m-TiO2载体使Ni和P物种的还原温度大幅度降低,在450～600oC还原制得的Ni2P/m-TiO2催化剂的结构参数基本一致,比表面积均为90m2/g左右,具有很高的热稳定性和对二苯并噻吩的HDS催化性能.在相同的反应条件下,m-TiO2负载的Ni2P催化剂HDS性能最好,各载体负载的Ni2P催化剂活性大小顺序为Ni2P/m-TiO2〉Ni2P/SiO2〉Ni2P/P25.