正戊烷选择性氧化用VPO催化剂的合成新方法(英)

研究了 合成 Ｖ Ｐ Ｏ 催化剂 时还 原 溶剂 对 Ｖ Ｐ Ｏ 的结 构及 催 化性 能的 影 响． Ｖ Ｐ Ｏ 的 合 成方法如下 ： （１） Ｖ２ Ｏ５ 与 Ｈ３ Ｐ Ｏ４ 反 应生成磷 酸钒; （２） 用 不同 的还 原溶 剂还 原磷 酸钒 得到 Ｖ Ｐ Ｏ 催化剂前身 ; （３） 活化 Ｖ Ｐ Ｏ 催化 剂前身． 研究 的还原溶 剂有 ： 异 丁醇 、异 丁醇苯甲 醇、异丁 醇石 油醚和正己 醇． 结 果表明, 使用异 丁醇石 油醚 作还 原 溶剂 ,只 能生 成 Ｖ Ｏ Ｈ Ｐ Ｏ４·０５ Ｈ２ Ｏ 晶 体; 使 用其它溶剂 则会生 成 Ｖ Ｏ（ Ｈ２ Ｐ Ｏ４） ２ 和 Ｖ Ｏ Ｈ Ｐ Ｏ４·０５ Ｈ２ Ｏ 两种 晶体,但使 用的溶 剂生 成这 两种 晶体 的相对量大 不相同 ． 经 活 化 后, 不 同 还 原 溶 剂 合 成 的 Ｖ Ｐ Ｏ 只 含（ Ｖ Ｏ）２ Ｐ２ Ｏ７ 晶 相． 在 活 化 过 程 中, Ｖ Ｏ（ Ｈ２ Ｐ Ｏ４） ２ 转变成 无定形化 合物． Ｖ Ｏ Ｈ Ｐ Ｏ４·０５ Ｈ２ Ｏ 晶相 含量较 高的催化 剂前身, 经活 化后 催化剂中（ Ｖ Ｏ）２ Ｐ２ Ｏ７ 晶 相含量相 对较高 ,其催化活 性也相 对较高     

环戊烷选择性氧化用VPO催化剂的合成新方法

研究了ＶＰＯ催化剂时还原溶剂对ＶＰＯ的结构及催化性能的影响,ＶＰＯ的合成方法如下：（１）Ｖ２Ｏ５与Ｈ３ＰＯ４反应生成磷酸钒;（２）用不同的还原溶剂还原磷酸钒得到ＶＰＯ催化剂前身;（３）活化ＶＰＯ催化剂前身,研究的还原溶剂有;异丁醇,异丁醇－苯甲醇,异丁醇－石油醚和正己醇。结果表明,使用异丁醇－石油醚作还原溶剂,只能生成ＶＯＨＰＯ４．０．５Ｈ２Ｏ晶体;使用其它溶剂则会生成ＶＯ（Ｈ２ＰＯ４）２和ＶＯＨ     

水煤气变换反应的微观动力学分析──Cu基催化剂上H_2S中毒失活原因的 Monte Carlo 模拟研究

用ＢＯＣＭＰ方法及ＭｏｎｔｅＣａｒｌｏ模拟技术，对Ｈ２Ｓ导致Ｃｕ基催化剂失活的原因进行了计算分析。研究结果表明，当原料气中存在Ｈ２Ｓ时，ＷＧＳ反应的活化能明显高于无Ｈ２Ｓ时的活化能，随着表面Ｈ２Ｓ浓度的增大（θ＝０，０．１０，０．２５），反应的活化能也逐渐变大（其大小比为１∶１．３４∶３．３），究其原因可归结为Ｈ２Ｓ的存在使得反应物分子的吸附热减小，从而使Ｈ２Ｏ的解离吸附（ＷＧＳ反应的速控步骤）活化能增大。     

水煤气变换反应的微观动力学分析：Cu基催化剂上H2S中毒失活原因 …

用ＢＯＣ－ＭＰ方法及Ｍｏｎｔｅ Ｃａｒｌｏ模拟技术，对Ｈ２Ｓ导致Ｃｕ基催化剂失活的原因进行了计算分析。研究结果表明，当原料气中存在Ｈ２Ｓ时，ＷＧＳ反应的活化能明显高于无Ｈ２Ｓ时的活化能，随着表面Ｈ２Ｓ浓度的增大（θ＝０，０．１０，０．２５），反应的活化能也逐渐变大（其大小比为１：１．３４：３．３），究其原因可归结为Ｈ２Ｓ的存在使得反应物分子的吸附热减小，从而使Ｈ２Ｏ的解离吸附（ＷＧＳ反应的速控步骤     

COS对FT合成催化性能的影响

在５２４Ｋ、２．３１ＭＰａ和１８４５ｈ＾－１条件下，考察了合成气（Ｈ２／ＣＯ＝２．１）中ＣＯＳ浓度分别为５１．４、１２８．８、１６２．７和２４５．６ｐｐｍ对Ｆｅ－Ｃｕ－Ｋ工业催化剂ＦＴ合成催化性能的影响。实验表明，催化剂预先中毒比在线中毒速度快。大颗粒催化剂的抗硫能力比小颗粒催化剂强。催化剂ＦＴ合成失活速率与ＣＯＳ浓度有关，即高浓度条件下，催化剂的失活速率快。当温度为５２４Ｋ时，催化剂的失活速率最     

SO_4~（2－）－Fe_2O_3－Hβ－Al_2O_3催化剂制备方法对其表面性质和催化丙烯酸化反应性能的影响

首次以Ｈβ沸石为基础，采用一步浸渍法（Ａ）、机械研磨法（Ｂ）、沉积－沉淀法（Ｃ）及分步浸渍法（Ｄ）制备了ＳＯ－Ｆｅ２Ｏ３－Ｈβ－Ａｌ２Ｏ３催化剂，通过ＸＲＤ，ＸＰＳ，ＮＨ３－ＴＰＤ，ＦＴ－ＩＲ及化学吸附等手段对其物理化学性能进行了表征，并对其催化丙烯与异丙醇的酸化反应性能进行了评价．结果表明，在催化剂表面，ＳＯ，Ｆｅ２Ｏ３及Ｈβ沸石之间存在较强的化学作用，Ａ法和Ｃ法制备的催化剂具有明显的增强酸性；总酸量和Ｌ酸量增多，酸强度提高；该催化剂明显促进了丙烯醚化反应，其丙烯和异丙醇转化率分别由Ｈβ－Ａｌ２Ｏ３沸石的７．９８％和３５．１％提高到１４．８％和４０．０％，并发现该反应主要在Ｌ酸中心上进行．     

SDM－1型耐硫催化剂甲烷化反应动力学Ⅱ．宏观动力学模型

本文以工业应用为目的，采用内循环无梯度反应器，在５７３～６７３Ｋ，０．３０～１．２０ＭＰａ的条件下，原料气组成为Ｈ＿２５０～５４％，ＣＯ１１．７～２０．７％，ＣＨ＿４２．１～１４．３％，ＣＯ＿２６．４～１１．５％，Ｎ＿２１２．２～１８．１％范围内，研究了φ５×３ｍｍＳＤＭ－１型城市煤气耐硫甲烷化催化剂的宏观动力学方程。选择ＣＯ＋３Ｈ＿２＝ＣＨ＿４＋Ｈ＿２Ｏ（１）ＣＯ＋Ｈ＿２Ｏ＝ＣＯ＿２＋Ｈ＿２（２）为系统的独立反应，获得了可靠的动力学模型，井讨论了反应条件对甲烷化反应效率因子的影响。     

KI-醚类催化剂催化二氧化碳和环氧乙烷合成碳酸乙烯酯反应研究

合成了５个含有金属铁的环醚Ｆｅ（ＣＯ）３Ｌ（Ｌ１＝Ｐｈ２Ｐ（ＣＨ２ＣＨ２Ｏ）２ＣＨ２ＣＨ２ＰＰｈ２，Ｌ２＝Ｐｈ２Ｐ（ＣＨ２ＣＨ２Ｏ）４ＣＨ２ＣＨ２ＰＰｈ２，Ｌ３＝ＯＰｈ［（ＯＣＨ２ＣＨ２）ＰＰｈ２］２，Ｌ４＝ＯＰｈ［ＯＣＨ２ＣＨ２）２ＰＰｈ２］２）和［Ｆｅ（ＣＯ３）］２Ｌ５（Ｌ５＝［Ｐｈ２ＰＣＨ２ＣＨ２ＯＣＨ２ＣＨ２ＰＰｈ２］２）．对它们进行了元素分析，并用红外光谱和核磁共振谱进行了结构表征．用ＫＩ＋醚类为催化剂，催化二氧化碳与环氧乙烷反应生成碳酸乙烯酯，反应选择性大于９６．９％．催化机理为碱催化，催化剂的活性受醚的影响．能和Ｋ＋形成稳定配合物的醚可提高催化剂的活性．含金属铁的环醚和普通醚类相似，可以和钾离子作用，提高阴离子的亲核催化性能．     

SO_4~（2－）／ZrO_2超强酸催化剂的XPS研究

用ＸＰＳ技术对不同焙烧温度、不同Ｈ＿２ＳＯ＿４浓度制得的／ＺｒＯ＿２和不同反应温度下反应后／ＺｒＯ＿２超强酸催化剂的表面元素电子结合能及表面元素的相对含量进行了分析。结果表明，焙烧温度和反应温度对催化剂表面元素Ｚｒ、Ｏ和Ｓ的氧化态没有影响，但Ｚｒ和Ｏ的电子结合能随温度的升高而下降；Ｏ（－２）至少可归结为三种存在形式的氧；可以在催化剂表面富集，且当Ｈ＿２ＳＯ＿４浓度为０．５ｍｏｌ／Ｌ时，表面富集最显著；Ｈ＿２ＳＯ＿４浓度为１ｍｏｌ／Ｌ时，催化剂表面和总体含硫量都较高；太低和太高的Ｈ＿２ＳＯ＿４浓度时，催化剂表面和总体含硫量都很低。当焙烧温度高至８５３Ｋ或反应温度高至６２３Ｋ以后，催化剂表面含硫量迅速下降。此外，还对催化剂表面的Ｂｒｏｎｓｔｅｄ酸中心的存在形式和催化剂的失活进行了探讨。     

加压条件下MgO/BaCO_3催化剂上甲烷氧化偶联反应性能及失活 Ⅱ.催化剂表面结构对其催化性能的影响

用ＸＰＳ，ＣＯ２－ＴＰＤ及ＣＯ与ＣＨ４的恒温脉冲反应技术，深入研究加压失活ＭｇＯ／ＢａＣＯ３催化剂表面结构变化对其催化性能的影响．结果表明，加压失活催化剂表面活性氧物种Ｏ２－２离子浓度大大降低；表面晶格氧的流动性及晶格氧参与甲烷转化的能力都大大减弱；由于加压失活催化剂表面结构发生变化，ＭｇＯ和ＢａＣＯ３共同作用形成的强碱中心消失．     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.