临氢还原处理对Al2O3负载的CuO-MOx催化剂的影响

研究了Ｈ２预处理对Ａｌ２Ｏ３负载ＣｕＯ和ＣｕＯ－ＭＯｘ催化剂的作用。考察了Ｈ２处理时间、Ｈ２处理浓度以及多次还原氧化循环对ＣｕＯ系催化剂ＣＯ氧化活性的影响规律,并用原位还原氧化反应技术、ＸＰＳ对Ｈ２预处理的作用进行了研究。结果表明,ＣｕＯ－ＣｏＯ／Ａｌ２Ｏ３和ＣｕＯ－Ｃｅ２Ｏ３／Ａｌ２Ｏ３催化剂受Ｈ２还原处理后ＣＯ氧化活性明显增加,并随Ｈ２处理时间、处理浓度的增加而增强。而且催化剂的ＣＯ氧化活性还     

NH4HCO3对氧化铝孔结构的影响

ＮａＡｌＯ２溶液和ＣＯ２在低温下成胶,生成的沉淀为无定形氢氧化铝,拟薄水铝石或三水氧化铝;加入一定量的ＮＨ４ＨＣＯ３,控制一定的时间,温度和压力,氢氧化铝与ＮＨ４ＨＣＯ３作用生成片钠铝石ＮＨ４Ａｌ（ＯＨ）２ＣＯ３,经高温焙烧后可制香孔容为０．６－１．５ｍｌ／ｇ的大孔容氧化铝。     

Cu－Ag／γ－Al_2O_3催化剂的还原特性及对苯的氧化活性

Ｃｕ－Ａｇ／γ－Ａｌ_２Ｏ_３催化剂的还原特性及对苯的氧化活性朱波，陈平，罗孟飞，袁贤鑫（杭州大学化学系，杭州３１００２８）吴红丽（杭州大学中心实验室，杭州３１００２８）关键词Ｃｕ－Ａｇ／γ－Ａｌ_２Ｏ_３催化剂，还原特性，苯的完全氧化反应，氧化活性．１...     

Cu－Ag－Mn－Ce－O／γ－Al_2O_3催化剂对CH_3OH及CO深度氧化时各元素的相互作用

Ｃｕ－Ａｇ－Ｍｎ－Ｃｅ－Ｏ／γ－Ａｌ_２Ｏ_３催化剂对ＣＨ_３ＯＨ及ＣＯ深度氧化时各元素的相互作用王金安，许勇，汪仁（华东理工大学工业催化研究所，上海２００２３７）关键词Ｃｕ－Ａｇ－Ｍｎ－Ｃｅ－Ｏ／γ－Ａｌ_２Ｏ_３催化剂，深度氧化，甲醇，一氧化碳，相互?..     

MoO3/TiO2-Al2O3对H2S吸附的XPS研究

应用ＸＰＳ对ＭｏＯ３／ＴｉＯ２－Ａｌ２Ｏ３体系的ＭｏＯ３在ＴｉＯ２－Ａｌ２Ｏ３载体上的存在状态及其对Ｈ２Ｓ的吸附和脱附性能进行了表征，结果表明：ＭｏＯ３在ＴｉＯ２－Ａｌ２Ｏ３表面存在分散状态的不同，这导致了对Ｈ２Ｓ吸附性能的不同，在相同的条件下，吸附剂的０．１５ｇＭｏＯ３／ｇＴｉＯ２－Ａｌ２Ｏ３时具有最大载硫量，且随吸附温度的升高载硫量也增加，达饱和对Ｓ／Ｍｏ原子比接近１，较好的氧化脱附温度为１５     

Pt－Mo／Al_2O_3和Pt－Co－Mo／Al_2O_3催化剂中Pt、Co助

利用ＴＰＲ、Ｈ_２－ＴＰＤ技术，考察了氢气氛下的Ｐｔ－Ｍｏ／Ａｌ_２Ｏ_３和Ｐｔ－Ｃｏ－Ｍｏ／Ａｌ_２Ｏ_３催化体系中物种和电荷交换的现象和规律，揭示了Ｐｔ和Ｃｏ在表面Ｍｏ物种还原过程中助剂作用的本质．Ｐｔ－Ｍｏ／Ａｌ_２Ｏ_３的ＴＰＲ、Ｈ_２－ＴＰＤ结果证明，由于微量Ｐｔ参与了表面Ｍｏ物种还原时的物种和电子交换，有效地降低了其还原温度．Ｒｔ－Ｍｏ／Ａｌ_２Ｏ_３在氢还原过程中，氢和Ｍｏ容易形成载有活动氢的氢物种，并储存在催化剂表面，这种活动氢在Ａｒ中，甚至Ａｒ－Ｈ２混合气中可以释放出来。Ｐｔ－Ｃｏ－Ｍｏ／Ａｌ２Ｏ３的研究结果表明，Ｃｏ可以进一步促进Ｍｏ的还原．在样品预还原过程中，氢和Ｃｏ可以形成氢物种，其上的氢具有更强的可动性，很容易溢流到Ｍｏ物种的边上促进其还原．根据以上规律可以推测，加氢脱硫催化剂中Ｃｏ和贵金属的作用是使催化剂更容易形成低价的配位不饱和的钼中心，也就是ＨＤＳ活性中心．     

助剂Ag对Cr／γ—Al2O3氧化物催化剂CO氧化性能的影响

本文用硝酸盐水溶液等浸渍法制备了一系列Ｃｒ－Ａｇ／γ－Ａｌ２Ｏ３双金属及单金属的 物催化剂，测定了ＣＯ氧化转化率。用ＢＥＴ，ＸＲＤ，ＴＰＲ，ＴＰＤ－ＭＳ技术研究了助剂Ａｇ对Ｃｒ／γ－Ａｌ２Ｏ３催化剂ＣＯ氧化反应的作用。     

甲烷部分氧化制合成气反应Pt/Al_2O_3和Pt/CeO2/Al_2O_3催化剂的研究(英文)

研究了Ｐｔ／Ａｌ２Ｏ３和Ｐｔ／ＣｅＯ２／Ａｌ２Ｏ３催化剂对甲烷部分氧化制合成气反应的催化活性，发现Ｐｔ／ＣｅＯ２／Ａｌ２Ｏ３显示了比Ｐｔ／Ａｌ２Ｏ３更高的甲烷转化率和合成气选择性。用Ｈ２ＴＰＲ，Ｈ２ＴＰＤ，ＳＥＭ和ＸＲＤ等手段和技术对催化剂进行了表征。ＣｅＯ２与Ｐｔ之间存在较强的相互作用（ＳＭＳＩ），这种作用促进了Ｐｔ在催化剂表面的分散，抑制了Ｐｔ在催化剂表面的迁移，大大降低了催化剂在反应中的完全燃烧活性，提高了催化剂的部分氧化活性和选择性，避免了因催化剂床层局部温度过高而导致催化剂活性下降或失活，提高了催化剂的稳定性。同时，在反应过程中，ＣｅＯ２通过促进水蒸气变换反应（ＷＧＳＲ）的进行使反应体系迅速达到平衡，提高了催化剂对Ｈ２的选择性。     

异丁烷催化脱氢制异丁烯Cr2O3／Al2O3体系催化剂

对异丁烷催化脱氢催化剂进行了研究。助催化剂Ｋ２Ｏ,ＣｕＯ的引入改进了Ｃｒ２Ｏ３／Ａｌ２Ｏ３催化剂的活性和抗积炭性能。同时考察了原料气空速、反应温度以及催化剂制备的焙烧温度对Ｋ２Ｏ－ＣｕＯ－Ｃｒ２Ｏ３／Ａｌ２Ｏ３催化剂反应性能的影响。ＸＲＤ谱图表明,Ｃｒ２Ｏ３在催化剂中高分散,７００℃焙烧的催化剂中出现的ＫＣｕＯ晶相对催化剂活性不利。用ＮＨ３－ＴＰＤ和ＣＯ２－ＴＰＤ检测了催化剂表面的酸碱中心,表明助     

Ni/Al2O3催化剂上甲烷部分氧化制合成气反应机理

用变应答／质谱在线检测技术研究了Ｎｉ／Ａｌ２Ｏ３催化剂上甲烷部分氧化制合成气的反应要理，研究结果指出，在常压９７３Ｋ条件下，Ｎｉ／Ａｌ２Ｏ３催化剂上甲烷部分氧化制合成气按直接氧化机理进行，Ｈ２和Ｃ烛甲烷部分氧化的一次产物，其主要反应可表示如下：１．ＣＨ４＋ｘＮｉ－ＮｉｘＣ＋２Ｈ２，２．Ｏ２＋２Ｎｉ－２ＮｉＯ，３．ＮｉｘＣ＋ＮｉＯ－ＣＯ＋（ｘ＋１）Ｎｉ。     

氯铬酸甲铵/硅胶载体氧化剂的制备及其对醇的氧化研究

利用硅胶作载体，负载氯铬酸甲铵盐制备了一种新的载体铬(Ⅵ)氧化剂。该试剂制备方法简单、性质稳定。可在多种反应介质中对伯醇和仲醇氧化，高收率得到相应的醛和酮，反应操作简单，提纯方便。     

盐酸三甲胺三氧化铬／硅胶载体试剂的制备及其对苯偶姻体系的氧化

报道了盐酸三甲胺三氧化锆／硅胶载体试剂的制备方法及其对苯偶姻的氧化反应。该试剂制备简单，用于地苯偶姻的氧化，高收率地得到相应的苯偶酰在化合物，并且反应条件温和，产物易分离。     

氯铬酸三甲铵/氧化铝的制备及其对醇和苯偶姻类化合物的氧化

本文报道了氯铬酸三甲铵/氧化铝的制备方法及其对醇和苯偶姻类化合物的氧化反应。 该试剂制备简单、性质稳定。氧化反应条件温和、操作简单、提纯方便、收率良好。     

三氟乙酸和三氟化硼乙醚在硫杂卟啉合成中的应用

利用三氟乙酸和三氟化硼乙醚在醇羟基与吡咯反应中的催化活性差异, 使非对称取代噻吩双醇中的羟基选择性地与吡咯反应, 得到单吡咯或双吡咯中间体. 这些中间体经进一步的环化反应, 得到一系列21,23-二硫杂卟啉衍生物, 并通过核磁共振氢谱、质谱、紫外-可见光谱和荧光光谱对其结构进行了表征.     

Synthesis and crystal structure of 2-{5-[2-(2,6-dichlorophenylamino)benzyl]-4-p-tolyl-4H-1,2,4-triazol-3-ylthio}acetate

The compound 2-{5-[2-(2,6-dichlorophenylamino)benzyl]-4-p-tolyl-4H-1,2,4-triazol-3-ylthio}acetate has been prepared and characterized by IR, ¹H NMR, ¹³C NMR and mass spectra. The crystal and molecular structure were further confirmed using single crystal X-ray diffraction. The crystal structure has been found to be stabilized by intermolecular C–H···O interaction generating bifurcated hydrogen bonds whereas the C–H···N interactions generate chain of molecules. The intramolecular N–H···N hydrogen bond forms a ring with S(7) graph-set motif.     

(PhCH2PPh3)+Br3 −: A Versatile Reagent for the Chemoselective Oxidation of Sulfides to Sulfoxides

Benzyltriphenylphosphonium tribromide (BTPTB), as a stable solid reagent, is easily prepared by the reaction of benzyltriphenylphosphonium bromide with Br₂. This reagent can be used as an efficient reagent for the chemoselective oxidation of dialkyl and aryl-alkyl sulfides to their corresponding sulfoxides in the presence of diaryl sulfides and primary alcohols. All reactions were performed in a refluxing mixture of methanol and water in very short reaction times.     

Rapid and Efficient Synthesis of Diaryl Carbazones using Microwave Technology

Diaryl carbazone is an important organic analytical reagent normally prepared by the oxidation of diaryl carbazine, but in literatures' methods, the yields were low and the procedures were trouble1,2. Recently, our laboratory reported some new methods for the preparation of diaryl carbazone from diaryl carbazine3,4. Generally, these methods have drawbacks such as tedious operation3, using large amounts of volatile and poisonous solvent which will pollute the environment inevitably3, long reaction time and complicated oxidation system4. In continuation of our studies on the synthesis of azo compounds, we decided to develop a new method to overcome the limitation.As we know, the application of microwave techniques for organic synthesis has attracted considerable interests in recent years5. Using microwave technology can enhance the selectivity and reactivity, increase the chemical yields and shorten the reaction time6. It has been widely used in a variety of organic reactions7,8. However, the synthesis of diaryl carbazones using microwave has not been reported so far.In this paper, a rapid and efficient synthesis of diaryl carbazones with NaBrO3/H2SO4 as oxidation system using microwave technology is reported for the first time. By this method, in short time (0.5 rmin), we have synthesized ten diaryl carbazones in good yields.In the oxidation study, we found that the acidic condition is necessary in these reactions.This method only needs cheap and easily available oxidants, simple instruments and easy work-up.In conclusion, It is a facile and rapid method for the preparation of diaryl carbazones from diaryl carbazines with NaBrO3/H2SO4.     

A solvent and transition metal-free,highly efficient Brønsted acidic ionic liquid promoted one-potthree-component reactions for the synthesis of tetrasubstituted pyrroles

Abstract

The present protocol describes a highly efficient, transition metal and solvent-free one-pot annulation of amines, dialkyl acetylenedicarboxylates and β-nitrostyrene using imidazolium Brønsted acidic ionic liquid for the synthesis of tetrasubstituted pyrroles. A diverse functionalized tetrasubstituted pyrroles derivatives were obtained with excellent yields under transition metal and solvent-free conditions. The Brønsted acidic ionic liquid can be easily recovered and reused for the next reaction without any effects on the yields of the products. This green protocol provides structurally complex, medicinally important tetrasubstituted pyrroles with various substitution patterns in a one-pot operation.     

Preparation of synthetic auxin-amino acid conjugates

Auxin amide conjugates are regulators of the most important auxin, indole-3-acetic acid (IAA), which is considered responsible for many important processes within the plants. Herein, amide conjugates of IAA were synthesized employing a simple and efficient coupling method with WSCI·HCl, a water-soluble condensing reagent, in the presence of 1-hydroxybenzotriazole. IAA conjugates with 10 amino acids along with their corresponding methyl esters were prepared in excellent yields, up to 95%, aiming to facilitate their identification in plant species. Eight IAA-amino acid methyl ester conjugates are characterized here for the first time.     

Ferrous Sulfide/Aqueous Ammonia: Simple,Efficient, and Chemoselective Reagent for the Conversion of Aromatic Azide to Amine

A practical, environmentally benign, rapid, and efficient method for the reduction of aromatic azide to amine is described using FeS/aqueous ammonia in the presence of other reducible functionalities. Application of a novel reducing reagent results in aromatic amines with excellent yield and high chemoselectivity, without need of any purification techniques.