负载于r－Al_2O_3、SiO_2担体上的四核金属羰基簇合物K［CoFe_3

本文采用无水无氧操作技术，合成了空气中不稳定的四核金属羰基簇合物Ｋ［ＣｏＦｅ＿３（ＣＯ）＿（１３）］，并将其负载于ｒ－Ａｌ＿２Ｏ＿３、ＳｉＯ＿２担体上，制成负载型双金属簇催化剂．分别于真空和ＣＯ气氛下，利用原位红外光谱表征了负载双金属羰基簇合物的热脱碳过程，获得了金属簇骨架（ＣｏＦｅ＿３）与担体表面原子相互作用的实验数据。     

薄层光谱电化学方法对DMSO溶液中O2与CoTPP相互作用的研究

循环伏安常规的光谱检测手段无法揭示非水溶剂中Ｏ２与ＣｏＴＰＰ的相互作用，本实验采用薄层光谱电化学方法揭示Ｏ２与ＣｏＴＰＰ的相互作用为Ｃｏ（Ⅰ）ＴＰＰ＋Ｏ２＝Ｃｏ（Ⅱ）ＴＰＰ＋Ｏ２，由于非水溶剂中Ｃｏ（Ⅱ）／Ｃｏ（Ⅰ）与Ｏ２／Ｏ２的氧化还原电位非非常接近，所以ＣｏＴＰＰ对Ｏ２的还原没有催化作用。     

二氧化碳和丙烷反应制取低碳烯烃的研究

采用 ＮＨ＿３－ＴＰＤ．Ｈ＿２－ＴＰＲ等手段对 Ｃｒ＿２Ｏ＿３／γ－Ａｌ＿２Ｏ＿３．Ｃｒ＿２Ｏ＿３／ＳｉＯ＿２，Ｃｒ＿２Ｏ＿３／ＺｒＯ＿２和Ｃｒ＿２Ｏ＿３／硅藻土等催化剂的酸性和还原性进行了表征；以Ｃ～０＿３＋ＣＯ＿２做探针反应研究了该系列催化剂的催化性能．ＮＨ＿３－ＴＰＤ结果表明．ＮＨ＿３ 在催化剂 Ｃｒ＿２Ｏ＿３／γ－Ａｌ＿２Ｏ＿３上的脱附量最多．而在Ｃｒ＿２Ｏ＿３／ＳｉＯ＿２上的脱附强度最大．Ｈ＿２－ＴＰＲ结果指出活性中心 Ｃｒ～（３－）在各催化剂上存在明显不同．Ｃ＿３＋ＣＯ＿２反应结果表明，丙烷在 Ｃｒ＿２Ｏ＿３／γ－Ａｌ＿２Ｏ＿３上的转化率最大为 ４４．１７％。而 Ｃ～－＿２～Ｃ～＿３在 Ｃｒ＿２Ｏ＿３／ＳｉＯ＿２上的选择性最大为８２．８４％．     

Cd~（2＋）与Cu~（2＋）、Co~（2＋）、Ni~（2＋）的非有机溶剂萃取分离研究

本文研究了ＰＥＧ－Ｚｉｎｃｏｎ－（ＮＨ＿４）＿２ＳＯ＿４体系对Ｃｕ~（２＋）、Ｃｏ~（２＋）、Ｎｉ~（２＋）、Ｃｄ~（２＋）的非有机溶剂萃取行为，结果表明：在ｐＨ５．５～８．５（Ｋ＿２ＨＰＯ＿４－ＫＨ＿２ＰＯ＿４）的水溶液中，Ｃｕ~（２＋）、Ｃｏ~（２＋）、Ｎｉ~（２＋）可被ＰＥＧ相几乎完全萃取，而Ｃｄ~（２＋）基本上不被萃取，从而获得了Ｃｄ~（２＋）与Ｃｕ~（２＋）、Ｃｏ~（２＋）、Ｎｉ~（２＋）混合离子的定量分离。     

高分子负载希夫碱的金属配合物的研究

合成了聚氯乙烯（ＰＶＣ）负载希夫碱的Ｃｏ（Ⅱ）、Ｎｉ（Ⅱ）、Ｌａ（Ⅲ）金属配合物，并考察了它们对Ｈ＿２Ｏ＿２的催化分解作用，发现催化活性顺序为：Ｃｏ（Ⅱ）＞Ｎｉ（Ⅱ），没有发现Ｌａ（Ⅲ）配合物有催化活性。     

混合负载型双金属簇催化剂的CO加氢反应

本文制备了两种类型的双金属簇催化剂［Ｆｅ·ＣＯ＿３·Ｃｕ·ＡＬ＿２Ｏ＿３］和［ＫＣＯＦｅ＿３．ＳｉＯ＿２］，评价了其在ＣＯ加氢反应中的催化性能，并考察了混合的双金属簇催化剂对ＣＯ加氢反应催化活性和选择性的影响。     

CaO－Al_2O_3－SiO_2玻璃表面上晶体生长动力学和分相影响

ＣａＯ－Ａｌ＿２Ｏ＿３－ＳｉＯ＿２玻璃表面上晶体生长动力学和分相影响杨晓晶，李家治（中国科学院上海硅酸盐研究所２０００５０）许淑惠（西北轻工业学院７１２０８１）ＳｕｒｆａｃｅＣｒｙｓｔａｌＧｒｏｗｔｈＫｉｎｅｔｉｃｓｉｎＣａＯ－Ａｌ＿２Ｏ＿３－ＳｉＯ...     

疏水硅沸石──一种新型环保用吸附剂

本文报道了疏水硅沸石（Ｓｉｌｉｃａｌｉｔｅ－Ⅰ）对小分子烷烃、芳烃、含氧有机物（醇、酸、酯、酮、醛）、氯代烷、萘及酚的饱和吸附量，以及氟利昂Ｆ－１２、ＳＯ＿２、ＣＯ＿２、ＣＯ空气在该沸石上吸附──脱附等温线。疏水硅沸石吸附剂能有效地从水中除去并回收小分子有机物，或从含水汽的空气中，分离并浓缩有害气体Ｆ－１２、ＳＯ＿２及ＣＯ＿２等。     

SiC_w一AlN复合材料工艺因素的研究

本文研究了工艺因素（烧结温度、添加剂组成和含量）对ＳｉＣ＿ｗ一ＡＩＮ复合材料的影响。结果表明：１８５０℃是较合适的复合材料烧结温度，复合材料力学性能与添加剂组成和含量有密切关系。Ｙ＿２Ｏ＿３与ＳｉＯ＿２在烧结中起的作用不同，Ｙ＿２Ｏ＿３与ＡＩＮ表面的Ａｌ＿２Ｏ＿３形成液相，是一种良好的烧结添加剂，而ＳｉＯ＿２由于与ＡＩＮ形成２７ＲＳｉａｌｏｎ多形体，反而阻碍材料致密化。在添加８ｗｔ％左右Ｙ＿２Ｏ＿３时。复合材料力学性能最佳，抗折强度σ５２０ＭＰａ，断裂韧性Ｋ＿（ｌｃ）＝４．９８ＭＰａ·ｍ￣（１／２）     

4氨基吡啶的合成

４－氨基吡啶（Ⅰ）是有机合成和医药合成的中间体，也是合成新型降压药吡那地尔（Ｐｉｎａｃｉｄｉｌ）的重要原料。Ⅰ作为分析试剂，其合成路线［１］如下：ＮＣＯＣＯＯ，Ｈ２Ｏ２→ＮＯＨ＋·ＣＯＯ－ＣＯＯＨＨＣｌ→ＮＯＨ＋·Ｃｌ－ＫＮＯ３，Ｈ２ＳＯ４→Ｎ（Ⅱ）...     

焙烧温度对Co-Ru-ZrO2/γ-Al2O3F-T合成催化剂性能的影响

采用浸渍法制备钴基催化剂,考察了催化剂焙烧温度对其F-T合成反应性能和产物分布的影响。制备催化剂时,不对催化剂进行焙烧,Co物种容易还原,并可较好分散,催化剂具有较高的催化活性和重质烃选择性。较高温度下焙烧,Co物种和载体间的相互作用增强,形成难还原的铝酸钴化合物,同时氧化钴晶粒聚集或烧结,Co物种的还原程度下降,催化剂CO加氢活性降低,重质烃选择性下降。在原料气n(H₂)∶n(CO)=2.0、483 K、1.5 MPa和800 h^-1条件下,未焙烧、673 K和923 K焙烧的催化剂上进行F-T合成反应,CO的转化率分别为80.27%、78.41%和61.14%,重质烃的选择性C₅⁺分别为88.54%、88.57%和77.95%。较低焙烧温度有利于反应速率的提高和重质烃的合成,较高焙烧温度使CO加氢活性下降,有利于低碳烃的生成。     

Reaction performance and characterization of Co/Al2O3 Fischer–Tropsch catalysts promoted with Pt, Pd and Ru

A series of noble metal (Pt, Ru or Pd) promoted Co/Al₂O₃ catalysts were prepared by sequential impregnation method. The catalysts were characterized by XRD, TPR, H₂-TPD and TPSR techniques, and their catalytic performance in Fischer–Tropsch synthesis was investigated in a fixed-bed reactor. The results of activity measurements show that the addition of small amounts of noble metal greatly improved the activity of the Co/Al₂O₃ catalyst. TPR experimental results demonstrate that hydrogen spillover from the noble metal to cobalt oxide clusters facilitated the reduction of cobalt oxide and, thus significantly increased the reducibility of Co/Al₂O₃ catalyst. The presence of noble metal increased the amount of chemisorbed hydrogen and weakened the bond strength of Co–H. TPSR results indicate that CO was adsorbed in a more reactive state on the promoted catalysts.     

焙烧温度对双金属催化剂甲苯加氢重整反应催化性能的影响

以类层柱Ni-Co/Mg(Al)O水滑石为前驱体,经不同温度焙烧制备了系列焦炉煤气中焦油模型化合物甲苯加氢重整制合成气催化剂. 在常压、反应温度800℃、水/碳摩尔比0.7和体积空速12000 h-1的条件下,在35 h评价时间内850℃焙烧的催化剂可完全转化甲苯,CH4和CO的平均产率分别为34%和66%,而低于750和高于950℃焙烧的催化剂活性较差. 850℃焙烧时催化剂比表面积较大,形成了尖晶石和固溶体,活性金属与载体间的相互作用较强,还原后活性金属颗粒小且均匀分布. 催化剂上有少量须状碳生成,绝大部分积碳可被H2消除,积碳是可逆过程.     

焙烧温度对Ru/Ba-Mg(Al)O4氨合成催化剂性能影响

采用超声-沉淀-强静电吸附法制备了化学性质比较稳定的掺钡纳米镁铝复合氧化物Ba-Mg(Al)O₄,并以其为载体、Ru₃(CO)₁₂为活性组分前驱体,制备了一系列钌基氨合成催化剂。通过场发射扫描电镜、X射线衍射和N2物理吸附等表征手段,重点考察了焙烧温度对载体的物相组成和表面织构的影响。结果表明,随着焙烧温度的升高,制备的载体比表面积逐渐下降,表面碱性增强。当载体焙烧温度为780 ℃时,制备的负载型Ru/Ba-Mg(Al)O₄催化剂表现出较高的催化活性,在425 ℃、10 MPa和10 000 h^-1条件下,出口氨浓度达到49.17 mmol·(g·h)^-1。     

Characterizations of Ru/ZnO catalysts with different Ru contents for selective hydrogenation of crotonaldehyde

Ru catalysts supported on ZnO with different Ru contents were prepared by an impregnation method and were applied to the vapor-phase selective hydrogenation of crotonaldehyde. The catalysts were characterized by X-ray powder diffraction (XRD), NH₃ temperature-programmed desorption (NH₃-TPD), transmission electron microscopy (TEM) and temperature-programmed oxidation (TPO). It was found that with increasing Ru contents in the Ru/ZnO catalysts, the activity (TOF), surface acidity amount and deactivation rate increased and the selectivity to crotyl alcohol increased first and then decreased. The 3Ru/ZnO catalyst showed the highest selectivity to crotyl alcohol (up to 88.0%) for the hydrogenation of crotonaldehyde. The initial TOF values of the catalysts depended on the strength of surface acidity and the Ru particle sizes. The more Lewis acid sites made catalysts deactivate more easily. It was assumed that the deactivation was due to the formation of organic compounds deposition and poison effect of CO strongly adsorbed on the Ru atoms.     

Vapor-phase selective hydrogenation of maleic anhydride to succinic anhydride over Ni/TiO2 catalysts

A series of supported Ni/TiO₂ catalysts were prepared by incipient wetness impregnation method under different calcination temperatures, and the as-prepared catalysts were characterized by X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H₂-TPR) and X-ray photoelectron spectroscopy (XPS). The catalytic properties of these Ni/TiO₂ catalysts were investigated in the vapor phase hydrogenation of maleic anhydride (MA) to succinic anhydride (SA). The results showed that the catalytic activity and the selectivity of the Ni/TiO₂ catalysts were strongly affected by the calcination temperature. The catalyst calcined at 1023 K showed a relatively higher SA selectivity of 96% at high MA conversion (96%) under the tested conditions (493 K and 0.2 MPa). The improvement of SA selectivity could be mainly assigned to the presence of suitable metal–support interaction, which can play a role in catalytic property of active nickel species as electron promoter. Besides, the change of surface properties of TiO₂ support with the increasing calcination temperatures, e.g., the decrease of Lewis acid sites, might also have some positive role in reducing the side-products like γ-butyrolacetone (GBL).     

The interaction of cobalt species with alumina on Co/Al2O3 catalysts prepared by atomic layer deposition

Alumina supported cobalt catalysts were prepared by atomic layer deposition (ALD) of cobalt acetylacetonate precursors (Co(acac)₂ and Co(acac)₃). The main modes of interaction between the acetylacetonate precursors and the support were found to be the exchange reaction between the alumina OH-groups and the acac-ligands of the precursor and dissociative adsorption on coordinatively unsaturated Al³⁺ sites. The amount of precursor that could adsorb on the support was determined by steric hindrance. Samples were prepared using 1–5 reaction cycles, i.e. subsequent precursor addition (Co(acac)₂) and calcination, resulting in catalysts containing ca. 3–10 wt.% Co. Samples were also prepared where the last calcination step was omitted, i.e. uncalcined catalysts. Calcination at 450 °C decreased the reducibility of the Co(acac)₂/Al₂O₃ catalysts due to formation of a cobalt oxide phase strongly interacting with the support and aluminate type surface species. The reducibility increased with metal loading on both calcined and uncalcined catalysts; however the reducibility of the calcined catalysts remained lower than of the uncalcined ones. The dispersion was found to be lower on the calcined catalysts. The cobalt particle sizes on the calcined samples was ca. 8 nm and on the uncalcined 4–5 nm, for cobalt loadings of ca. 6–10 wt.%. Catalytic activity was tested by gas phase hydrogenation of toluene in temperature programmed mode (30–150 °C).     

Production of Higher Hydrocarbons from CO2 over Nanosized Iron Catalysts

The effects of the particle size of a Fe/Cu/K catalyst on CO and CO₂ hydrogenation reactions as well as the variation of crucial factors such as surface area and basicity, reduction, carburization, and catalytic behavior of precipitated Fe/Cu/K catalysts were evaluated. Hematite nanoparticle catalysts with various surface tensions were produced by homogeneous precipitation in alcohol/water solvents. The basicity of the K‐promoted iron catalyst was higher in iron catalysts with lower particle size. The increase in K‐basic sites at the surface of catalysts with smaller particle size was attributed to their higher surface areas. Elevation of catalyst basicity led to considerably stronger dissociative CO adsorption. Shifting the oxygen removal pattern to lower temperature was the consequence of faster nucleation of FeCx crystallites on promoted surface oxides. CO₂ hydrogenation can occur in two distinct direct and indirect routes via the Fischer‐Tropsch mechanism.     

Deactivation of metal catalysts in liquid phase organic reactions

The paper gives a general survey of the factors contributing to the deactivation of metal catalysts employed in liquid phase reactions for the synthesis of fine or intermediate chemicals. The main causes of catalyst deactivation are particle sintering, metal and support leaching, deposition of inactive metal layers or polymeric species, and poisoning by strongly adsorbed species. Weakly adsorbed species, poisons at low surface coverage and solvents, may act as selectivity promoters or modifiers. Three examples of long term stability studies carried out in trickle-bed reactor (glucose to sorbitol hydrogenation on Ru/C catalysts, hydroxypropanal to 1,3-propanediol hydrogenation on Ru/TiO₂ catalysts, and wet air oxidation of paper pulp effluents on Ru/TiO₂) are discussed.     

MgFeMn-HTLcs的制备、改性及其CO加氢性能

采用沉淀-水热法制备了系列不同Mg/Fe/Mn配比的MgFeMn-HTLcs类水滑石前体,经焙烧、浸渍法K改性用于CO加氢制烯烃反应。采用XRD、SEM、TG、N₂吸附-脱附、H₂-TPR、XPS等手段对催化剂进行了表征。结果表明,制备的Mg-Fe-Mn前体均具有类水滑石层状结构,Mn的添加使结晶度下降;焙烧后,Mg-Fe样品主要生成MgO,Mg-Fe-Mn样品生成Mg₂MnO₄、MgO和MgFe₂O₄物相;反应后主要为MgCO₃和FeCO₃混合物相,伴随FeO-MnO和Fe_xC_y的生成;与K/Mg-Fe样品相比,Mn的加入进一步促进了Fe的分散,使得Fe₂O₃到Fe₃O₄还原度增加,其供电子效应促使Fe电子结合能向低偏移。在CO加氢反应中,K/Mg-Fe-Mn催化剂均表现出较高的反应活性和烯烃选择性。其中,K/3Mg-1Fe-2Mn催化剂的效果较好,CH₄含量较低,O/P值达5.20,C₂⁼～C₄⁼质量分数为43.03%。