CuO的添加方式对合成二甲醚反应中脱水性能的影响

CuO以不同的添加方式对-γA l2O3进行改性.用H2-TPR、还原态NH3-TPD、XRD表征技术以及浆态床CO H2合成二甲醚反应对催化剂的还原性能、还原态的酸中心分布、物相分布和反应活性进行了考察.H2-TPR结果表明,在沉积法制备的催化剂上可还原的氧化铜的量最大,且容易还原;还原态NH3-TPD结果说明了沉积法制备的催化剂上适合脱水反应进行的弱酸中心的比例最大;XRD结果发现在浸渍法制备的催化剂上,有少量的铜和铜铝化合物存在,其它方法制备的催化剂上CuO均匀分散在催化剂表面;目标反应的结果指出了沉积法制备的催化剂上,二甲醚的选择性最佳.     

Ce1-xNixO2/Al2O3/FeCrAl催化剂的制备及其甲烷催化燃烧性能

以FeCrA l合金薄片为基体,A l2O3为过渡载体,Ce1-xN ixO2(x=0.1-0.3)、CeO2和N iO为活性组分,制备了Ce1-xN ixO2/A l2O3/FeCrA l、CeO2/A l2O3/FeCrA l和N iO/A l2O3/FeCrA l金属基整体式催化剂,在固定床微型反应器中评价了催化剂的甲烷催化燃烧性能,用SEM、XRD、TPR等方法对催化剂的物相、表面形貌和氧化还原性进行了表征.结果表明,Ce1-xN ixO2在催化剂表面的分散性比CeO2和N iO要好;Ce1-xN ixO2/A l2O3/FeCrA l(x=0.1-0.3)催化剂具有好的催化活性和高温稳定性,CeO2/A l2O3/FeCrA l和N iO/A l2O3/FeCrA l催化剂有好的初活性但高温稳定性较差;活性组分与A l2O3和FeCrA l金属基体之间存在较强的相互作用.     

Ni-Al2O3催化剂上丙烷选择性还原NO

 以机械混合法、浸渍法和共沉淀法分别制备了4%Ni-Al2O3催化剂,并用X射线衍射、程序升温还原、紫外-可见漫反射光谱和N2吸附等方法对催化剂的体相和表面结构进行了表征,系统考察了制备方法及焙烧温度对Ni-Al2O3催化剂催化丙烷选择性还原NO性能的影响. 结果表明, Ni-Al2O3中存在NiO和NiAl2O4两种镍相,前者是丙烷氧化活性中心,后者是NO选择性催化还原的活性中心. 共沉淀法制备的催化剂活性最好, 550 ℃焙烧的Ni-Al2O3催化剂在反应温度为450和500 ℃时NO转化率接近100%.     

介孔纳米 MoPO-AlPO4 的制备及其对异丁烯选择氧化的催化性能

 分别采用溶胶-凝胶法和等体积浸渍法制备了 MoPO-AlPO4 催化剂, 考察了钼物种存在状态对催化剂晶格氧活性以及异丁烯选择氧化反应性能的影响. N2 吸附-脱附、X 射线衍射、高分辨透射电镜、X 射线光电子能谱、傅里叶变换红外光谱、程序升温还原和微反实验结果表明, 与浸渍法制备的催化剂相比, 溶胶-凝胶法制备的 MoPO-AlPO4 催化剂为介孔纳米材料, 其比表面积和孔数量均有较大程度的提高. 在浸渍法制备的催化剂中, 钼物种以四面体 MoO42− 和八表面体 MoO66− 形式存在; 而在溶胶-凝胶法制备的催化剂中钼物种主要以四面体 MoO42− 的形式存在, 并有部分钼物种嵌入到了 AlPO4 骨架中. 钼物种的种类对异丁烯选择氧化反应的活性和选择性有较大影响, 溶胶-凝胶法制备的催化剂由于嵌入 AlPO4 骨架中钼物种的存在, 异丁烯选择氧化反应性能得到较大提高.     

MgO改性的γ-Al2O3负载CuCl2-KCl催化剂上乙烷氧氯化制氯乙烯

采用浸渍法制备了不同含量MgO改性的γ-Al2O3,采用X射线衍射、N2物理吸附、NH3的程序升温脱附和程序升温还原等手段表征了催化剂的结构、表面酸性和氧化还原性质,并对CuCl2-KCl/MgO-Al2O3催化剂催化乙烷氧氯化制氯乙烯反应进行了活性评价.XRD结果表明,通过使用Mg(NO3)2溶液浸渍γ-Al2O3载体在表面上形成了表层镁铝尖晶石结构.TPR结果说明,表层MgAl2O4的生成加强了活性物种Cu与载体的作用,促进了CuⅡ→CuⅠ的还原.CuCl2-KCl/MgO-Al2O3催化剂对乙烷氧氯化反应的催化性能表明,随着MgO-Al2O3载体中MgO含量的增加,乙烷转化率和氯乙烯选择性逐渐升高,当MgO含量增加至10%时,氯乙烯的选择性最高(49.1%).NH3-TPD结果表明,表层MgAl2O4中和了γ-Al2O3表面的强酸中心,增加了弱酸中心的数量是氯乙烯选择性提高的主要原因.     

Mo-P-O/SiO2催化剂上的异丁烷选择氧化反应

 采用溶胶－凝胶法制备了MoO3／SiO2和Mo－P－O／SiO2催化剂，用X射线衍射、红外光谱、程序升温还原、程序升温脱附和活性评价等手段研究了催化剂的表面结构、晶格氧活泼性、化学吸附性能以及异丁烷选择氧化反应性能．结果表明，活性组分在催化剂表面分散较好；异丁烷吸附在催化剂表面Lewis碱位的MoO端氧上形成分子吸附态；MoO3／SiO2和Mo－P－O／SiO2两种催化剂对异丁烷选择氧化都有较好的选择性，将PO3－4引入到MoO3／SiO2催化剂中可提高含氧化合物的选择性     

乙烷氧化脱氢制乙烯CeO2-NiO/A2O3催化剂上氧物种的研究

在镍基催化剂上进行了乙烷氧化脱氢制乙烯的研究.结果表明,浸渍法制备的催化剂性能最佳.以浸渍法引入CeO2后,催化剂的低温反应活性显著提高.采用O2-TPD-MS、TPR和XPS等表征技术对催化剂进行了表征,结果显示:在ODE反应中,在低温下起主导作用的是"非化学计量氧"(O2-、O-和O22-);在高温下起主导作用的是晶格氧;CeO2的添加减弱了NiO与载体-γAl2O3间的强相互作用,提高了镍物种在载体上的分散度,高分散于催化剂表面的微晶NiO的量明显增加,此物种有利于催化剂的低温活性;影响了催化剂表面氧物种的分布,表面的晶格氧的相对浓度提高了,非化学计量氧的相对浓度降低了.     

WO3/(TiO2-SiO2)催化剂的表面分散状态及催化性能的研究

用气相流动吸附法制备复合载体,用浸渍法制备WO3/(TiO2-S iO2)催化剂.应用LRS和TPR技术研究WO3在复合载体TIO2-S iO2表面的分散状态,发现TiO2在S iO2表面的分散可增强WO3与载体之间的相互作用,提高WO3在载体表面的分散阈值.另外TPR实验证明,TiO2的存在不仅大大改善WO3的分散状态,而且使WO3在TiO2-S iO2的还原温度升高,WO3与载体之间的作用增强.负载于经TiO2调变的S iO2上的催化剂其HDS、HYD、BHD活性高于负载于单纯S iO2上的催化剂的活性.     

镍基催化剂上糠醛选择性加氢合成糠醇

采用浸渍法制备了一系列负载的Ni催化剂,用于糠醛选择性加氢反应.用XRD、TPR等手段对Ni/γ-Al2O3样品进行了表征.结果表明,Ni负载量在5~|15%范围内,高度分散于载体γ-Al2O3表面,Ni负载量进一步提高到20%,则在载体表面聚集成为微晶.在10%Ni/γ-Al2O3样品上提高焙烧温度有利于Ni的前驱体分解且高度分散于载体表面.Ni2 与γ-Al2O3存在较强的相互作用,但这种相互作用随着Ni负载量的增加而逐渐减弱,随着焙烧温度的增加而逐渐增强.与其他载体负载的Ni催化剂相比,Ni/γ-Al2O3由于其大的表面和适当的表面结构,在糠醛加氢反应中表现出一定的活性和较高的选择性,且随着Ni负载量的增加,活性逐渐增强,但选择性有所下降.另外催化剂的焙烧温度、还原温度,反应温度和溶剂对该反应均有较大影响,采用极性有机溶剂,适宜的焙烧和还原温度有利于催化剂活性和选择性的提高.     

浸渍钠对铁基催化剂F-T合成浆态床反应性能的影响

以FeCuK/Si O2为母体催化剂,通过乙酸钠浸渍得到一组不同Na含量的费托合成铁基催化剂.采用原子发射光谱、低温N2吸附、程序升温还原和M ssbauer谱等技术对催化剂进行了表征.在H2/CO摩尔比为0.67,空速为2 000 h-1,压力为1.5 MPa和温度为250℃的条件下进行了浆态床F-T合成反应性能评价实验.结果表明,浸渍少量Na能提高催化剂的比表面积,促进铁物相的分散,而浸渍大量Na却大大降低了催化剂的比表面积,使催化剂中的铁物相聚集形成较大的颗粒;浸渍Na抑制了催化剂在H2中的第一步还原,但促进了催化剂在CO中的碳化;在原位合成气还原过程中,浸渍Na有利于催化剂的碳化.在500 h的运行实验中,浸渍Na的催化剂均表现出不同程度的失活现象.反应结果表明,浸渍Na对水煤气变换反应活性影响不大,对费托合成反应活性和烃产物选择性有较大的影响.在铁基催化剂上浸渍Na有利于C12 重质烃和低碳烯烃的生成.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。