新型水溶性配体-负载金属氢甲酰化催化剂:TPPTS-Rh/SiO2

考察了几种硅胶负载贵金属催化剂和HRhCO(TPP)3催化剂的1-己烯氢甲酰化反应,对Rh/SiO2、 HRhCO(TPPTS)3/SiO2 和TPPTS-Rh/SiO2上的1-己烯氢甲酰化结果进行了比较.结果表明, TPPTS-Rh/SiO2催化剂的醛的选择性和醛的正异比n/b接近HRhCO(TPPTS)3/SiO2 的相应的催化性能,而远高于Rh/SiO2的相应的催化性能, 7.0 MPa高压下TPPTS-Rh/SiO2催化剂的活性大幅度增加,达到0.0692 S-1.实验排除了其他可能,认为是含有孤对电子的TPPTS 和Rh/SiO2中高度分散的Rh粒子产生了化学键的作用,形成了具有匀相性能的支撑水膜多相催化剂: TPPTS-Rh/SiO2.     

负载型非晶态Co-B催化剂在1-辛烯氢甲酰化中的应用

以醇凝胶-氮气热处理方法制备的ZrO2、碳纳米管(CNTs)及介孔分子筛SBA-15作为载体,采用化学还原法制备了负载型非晶态Co-B催化剂,利用粉末X射线衍射(XRD)、氮气吸附等温线、透射电子显微镜(TEM)、电感耦合等离子体-原子发射光谱(ICP-AES)以及X射线光电子能谱(XPS)等对催化剂进行了表征.以1-辛烯的氢甲酰化为目标反应,考察了负载型非晶态Co-B催化剂在氢甲酰化反应中的性能及循环使用效果.表征结果显示,以NaBH4为还原剂制备的负载型Co-B催化剂上的Co-B为非晶态,负载Co-B组分对载体的晶相结构没有影响.反应结果表明,在1-辛烯的氢甲酰化反应中,负载型非晶态Co-B催化剂都显示较高的初始活性.随着循环次数的增加,三种催化剂的活性下降,但下降幅度有所不同,Co-B/CNTs和Co-B/SBA-15的循环使用稳定性高于Co-B/ZrO2.     

高分散负载型Rh簇催化剂的研究

利用化学吸附及原位红外吸附态的测定装置和连续流动微反研究了用非传统方法制备的Rh_4/Al_2O_3和Rh_2/Al_2O_3。结果表明:催化剂具有高的金属分散度和均一的金属粒度;CO在催化剂上只有一种吸附方式,孪生吸附态;CO和H_2共吸附时,观测到的2035cm~(-1)谱带,归属为吸附态;在CO加氢反应中,催化剂具有高活性和高选择性,归结于高的金属分散度和均一的金属粒度。     

高分子负载金属催化剂的高分子效应

本文评述了高分子负载金属催化剂的分类及其高分子效应,重点评述了高分子负载金属络合物催化剂的载体功能基效应,多功能协同效应,高分子场效应和高分子基体效应,对高分子分散金属催化剂的高分子效应研究也作了一定的综述。     

碳纳米管负载铑催化剂上丙烯氢甲酰化

Effect of carbon nanotubes, as a novel support material, on the performance of Rh-catalyst supported by them was studied. Catalysts based on carbon nanotubes, SiO2, carbon molecular sieves, active carbon, and GDX-l02(a copolymer of styrene with divinylbenzene),were prepared, and their catalytic behaviors for propene hydroformylation were investigated and compared. The results showed that, over the carbon nanotubes-supported Rh-catalyst, C3H6 conversion and regioselectivity of butyric aldehyde (represented by n/i, a ratio of n-butyric aldehyde to its isomer, i-butyric aldehyde, in the products) were pronouncedly improved: the average turnover frequency(TOF) for the catalytic hydroformylation of propene was 0.079 s-1 at 393K, which was 2.1 times faster than that over the Rh catalyst based on SiO2, and the n/i ratio of the aldehyde products reached to 11.6, which was 1.9 times higher than that over the catalyst based on SiO2. The roles of six-membered C-ring at the surface of the carbon-nanotubes on the stability of the catalytically active Rh-complexes and of the tubular nano-channel on the spatiospecific seletivity of reaction intermediate state and butyric aldehyde produced were discussed.     

纤维素负载金属催化剂研究进展

高分子负载金属催化剂由于催化活性好、稳定性高、反应后容易和产物分离、易于从反应体系中分离回收和重复使用等原因,近年来成为了人们的研究热点之一。纤维素是自然界中储量最丰富的天然高分子,其在大多数有机溶剂中稳定,且其比表面积大,结构中含有大量羟基,可参与许多反应。本文以自然界中储量丰富、无毒、可降解、可再生的天然高分子纤维素为载体,按照纤维素负载金属催化剂制备方式的不同,综述了纤维素负载Pd、Ag、Au、Cu等金属催化剂的制备及其在有机反应中的应用。     

茂金属催化剂的负载化

负载化是茂金属催化剂发展的一个新方向。本文系统地描述了茂金属负载化催化剂的主要制备方法;分析了活性中心的本质、结构以及生成机理;并且讨论了负载化对茂金属催化剂烯烃聚合性能的影响。     

新型负载水相催化剂（SAPC）的制备及其在丙烯氢甲酰化反应中的应用

以新型水溶性二磺化 - 1-苯基二苯并膦 (简称 PDBPDS)为配体 ,制备了铑膦配合物 Rh(acac) (CO ) -(PDBPDS) 3.将其负载于高吸水性载体上 ,制得负载水相催化剂 ,并对催化剂的制备条件进行了优化 .以人造沸石为载体 ,在载水量 30 % ,[Rh]=2 .0× 10 - 5、 [P]/ [Rh]=40的条件下 ,筛选出丙烯氢甲酰化反应的最佳工艺条件 .在反应温度 10 0℃、压力 2 .0 MPa、搅拌速度为 5 0 0 r/ m in条件下 ,催化剂活性达 10 12 g丁醛 / (g Rh· h) ;正异比高达 43.5 ;在有机相中铑的浓度为 1.2× 10 - 9,解决了均相反应催化剂回收和循环使用的问题 .实验结果表明 ,新型配体二磺化 - 1-苯基二苯并膦是一性能较好的新配体 ,所制备的新型负载水相催化剂是一有较好开发前景的新型催化剂     

负载型钒基催化剂上丙烷的临氧活化转化

用ＴＰＳＲ（程序升湿表面反应）－ＴＲ（ＦＴ）ＩＲ技术,研究临氧条件下丙烷负载型钒基催化剂上的活化和转化,并与催化剂的可不原性和表面酸性相关联,丙烷氧化脱氢生成丙烯与深度氧化生成ＣＯｘ的起始反应温度相同;而裂解产物Ｃ２Ｈ４和ＣＨ４的生成温度比丙烷氧化脱氢生成丙烯的高得多,可能主要源于丙烷的高温气相裂解,催化剂的表面酸性位和强的可还原性,有利于丙烷中Ｃ－Ｈ键的活化和临氧转化,降低起以攻提高丙烷转化率,     

担载型铑络合物催化异丁烯氢甲酰化反应的研究

将铑络合物担载于磷钨酸改性的载体上制备了一系列新型催化剂。利用异丁烯氢的甲酰化反应考察了磷钨酸改性的各种载体对催化剂的活性和稳定性的影响。结果表明,以磷钨酸改性的S iO2为载体的催化剂在反应中的催化效果最好,当异丁烯5.0 g,V(H2)∶V(CO)=1∶1,p=3.0 MPa时,于377 K反应5 h,ASTY达420.9 h-1;异戊醛的收率为80.37%。     

新型的承载双金属氰化物络合催化剂

用双金属氰化物(DMC)络合催化剂可制得相对分子质量高、相对分子质量分布窄和不饱和度低的聚醚多元醇。为提高DMC催化剂的利用率,降低催化剂和聚醚的生产成本,国外开发了承载的DMC催化剂。它不仅可简化聚醚的后处理工艺,而且使聚醚的连续化大规模生产得以实现,因此代表了DMC催化剂的一个重要发展方向。     

负载型Pt催化剂上生物质水相重整制氢

制备了Al2O3,活性炭(AC),氢型超稳Y分子筛(HUSY)和SiO2载的Pt催化剂.采用N2物理吸附、感应耦合等离子体原子发射光谱和H2化学吸附等手段对催化剂进行了表征,并考察了它们在甘油水相重整反应中的催化性能.重点研究了Pt/AC催化剂上不同多元醇、葡萄糖和其它可溶性糖的水相重整制氢反应.结果表明,在甘油水相重整制氢反应中,负载Pt催化剂的活性在低温(503K)以Pt/AC,Pt/HUSY,Pt/SiO2和Pt/Al2O3的顺序递增,然而在高温(538K)却以Pt/SiO2,Pt/HUSY,PVAC和Pt/Al2O3的顺序递增.在载体为酸性的催化剂Pt/Al2O3和Pt/HUSY上有利于烃的生成;在多元醇水相重整制氢反应中,产物氢的选择性和产率随碳数增加而降低;在葡萄糖水相重整制氢反应中,产物氢的选择性和收率随其浓度增加而降低,烃选择性在葡萄糖浓度为4.6%时最高,这与葡萄糖的缩合和降解等副反应有关.果糖比葡萄糖更难发生水相重整制氢反应.与低级糖麦芽糖和葡萄糖相比,在多糖淀粉的重整制氢反应中氢选择性和收率较高.     

Surface Study of Supported Metal Catalysts

The aim of the reported studies was to determine the catalytic behaviour of M-C systems (M=Pt, Pd and Ru) towards hydrogenolysis of the C-X bond (X=Cl and F). The level of noble metal loading is reflected in the size of the metal clusters formed on the surface of the carbon support and affects the product distribution and the amount of carbonaceous deposit formed upon the conversion of CCl₂F₂. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cracking of Cellulose over Supported Metal Catalysts

Cellulose is cracked over supported Pt or Ru catalysts under hydrogenolysis conditions in water to give sorbitol as a main product. Among the catalysts tested, Pt/γ-Al₂O₃ gave the highest yield and selectivity, and this catalyst was recyclable in repeated runs. It is proposed that cellulose is hydrolyzed by in situ generated acid sites to form glucose, and glucose is immediately reduced to sorbitol over the metal catalyst.     

溶剂化金属原子浸渍法制备高分散载型催化剂 II. Fe,Co,Ni催化剂的分散度和催化性能研究

本文利用一种新的方法-溶剂化金属原子浸渍法制备了Fe/γ-Al_2O_3, Fe/SiO_2, Co/γ-Al_2O_3,Co/SiO_2, Ni/γ-Al_2O_3和Ni/SiO_2六种催化剂。H_2化学吸附, TEM和XRD测定结果表明这些催化剂中Fe, Co, Ni金属颗粒平均直径都小于3.0 nm, 金属分散度均大于50%。作者研究了Fe/γ-Al_2O_3, Co/γ-Al_2O_3和Ni/γ-Al_2O_3三种催化剂在CO+H_2反应中的催化行为, 测定了碳氢产物分布和比催化活性, 表明随着H_2/CO比增大和反应温度升高。较高分子量物种产量减少, 有利于生成甲烷。催化剂的活性大小次序为Fe>Ni>Co。     

A Rapid Method of Measurement Hydrogen Chemisorption on Supported Metal Catalyst

The surface area and dispersion of a supported metal catalyst can be conveniently determined form the measurement of a chemisorbed monolayer of an appropriate adsorbate such as hydrogen at conditions under which little or no adsorption occurs on the support. Such measurements can be carried out by means of conventional high-vacuum-adsorption apparatus^[1],but more rapid flow methods of measuring chemisorption are often found useful^[2]. This is especially true when the need arises to characterize the multitude of catalyst samples generated by varying preparation, support, pretreatment and use of a given series of supported metals.     

聚乙烯载体催化剂的制备与表征

不同目数的聚乙烯粉末通过辐射方法接枝了4-乙烯基吡啶官能团.经甲基铝氧烷(MAO)预处理后负载了茂金属催化剂Cp₂ZrCl₂.光电子能谱和红外光谱结果表明催化剂通过MAO的作用负载在聚乙烯接枝4-乙烯基吡啶聚合物上.4-乙烯基吡啶的接枝含量、催化剂的负载率以及载体催化剂对乙烯单体的活性均随着聚乙烯粉末的颗粒减小而增大.     

Production of Carbon Nanotubes on Different Metal Supported Catalysts

Multiwall carbon nanotubes have been prepared by catalytic chemical vapor deposition (CCVD) method in high yield using various metals supported on different supports. Measurements by transmission electron microscopy (TEM) revealed the presence of high quality nanotubes on each catalyst, however, comparing the different catalysts in nanotube production it can be stated that beyond metals, the support also affects both the quality and the quantity of nanotubes.