磷钨酸插层Zn/Al类水滑石催化合成邻苯二甲酸二(2-乙基)己酯

以对苯二甲酸根阴离子为预支撑体,制备了磷钨酸插层Zn/Al类水滑石杂化物催化剂,将其用于邻苯二甲酸二(2-乙基)己酯(DOP)的合成反应.研究了原料配比、催化剂用量、反应温度、反应时间等对邻苯二甲酸酐转化率的影响,及催化剂的可重复利用性.结果表明,磷钨酸-Zn/Al类水滑石杂化催化剂对DOP合成的催化效果较好,在催化剂用量为苯酐质量的0.76%,异辛醇与邻苯二甲酸酐的摩尔比为2.5,反应温度为180℃,反应时间为4.5 h,带水剂环己烷约为苯酐质量65%的反应条件下,苯酐转化率可达92.8%;反应10 h转化率可达97.9%.催化剂重复使用时转化率略有下降,经过乙醇洗涤再生,活性即可基本恢复.     

FCC汽油低温改质过程的烯烃转化及催化剂积炭

利用微反-色谱联合实验装置和连续式小型提升管催化裂化实验装置研究了催化裂化汽油低温改质过程中烯烃转化和催化剂积炭的过程和规律。通过对模型化合物和催化裂化汽油改质过程中催化剂活性、催化裂化汽油窄馏分、反应温度、剂油比和反应时间对烯烃转化和催化剂积炭的研究表明,大部分烯烃转化和催化剂积炭的反应发生在油剂接触极短的反应时间内,并随着催化剂活性、反应物活性、剂油比和反应温度的提高而增加。在油剂接触后很长的反应时间内,生焦量、积炭速率和烯烃的转化程度都很小,烯烃转化损失率降低,因此,催化裂化汽油在低温改质的条件下可以通过延长反应时间来提高烯烃的转化率。因此,催化裂化汽油改质的最佳工艺条件为,390℃～440℃,剂油比6,催化剂活性61～65,长反应时间,轻馏分进料。     

壳聚糖席夫碱钯配合物催化碘代苯与苯乙烯交叉偶联反应的研究

水杨醛与壳聚糖反应制得壳聚糖席夫碱配体,此配体与钯盐反应得到壳聚糖席夫碱钯催化剂.研究了该催化剂对碘代苯(PhI)与苯乙烯偶联生成反式-二苯乙烯的催化性能.考察了不同反应因素(原料比、缚酸剂种类及其用量、反应温度、溶剂、催化剂用量、反应时间)对该反应的影响,由此确定了该催化反应的最佳反应条件.该催化剂经过滤分离、溶剂洗涤,循环使用6次仍有较高的催化活性,该催化剂对取代碘苯与苯乙烯的反应也有较高的催化活性.     

乙炔氢氯化反应铜系催化剂的反应机理

以电石乙炔法制备氯乙烯的非汞催化反应体系为研究对象,用量子化学密度泛函理论(DFT)研究了以Cu基催化剂为代表的非汞催化剂的反应机理.模拟了以石墨烯为载体的乙炔氢氯化反应在Cu基催化剂作用下的两条反应路径及其过渡态.将该反应机理应用到不同金属氯化物催化剂中,通过计算相应的活化自由能和反应速率常数讨论了不同金属氯化物的活性顺序,与实验结果相比较印证了反应机理的合理性.讨论了Cu基催化剂的失活原因以及在载体中掺杂氮原子或磷原子对反应活性的影响.为非贵金属无汞催化剂的研究提供了一定的理论指导.     

Toward De Novo Catalyst Discovery: Fast Identification of New Catalyst Candidates for Alcohol-Mediated Morita–Baylis–Hillman Reactions**

Recently we have demonstrated how a genetic algorithm (GA) starting from random tertiary amines can be used to discover a new and efficient catalyst for the alcohol-mediated Morita–Baylis–Hillman (MBH) reaction. In particular, the discovered catalyst was shown experimentally to be eight times more active than DABCO, commonly used to catalyze the MBH reaction. This represents a breakthrough in using generative models for catalyst optimization. However, the GA procedure, and hence discovery, relied on two important pieces of information; 1) the knowledge that tertiary amines catalyze the reaction and 2) the mechanism and reaction profile for the catalyzed reaction, in particular the transition state structure of the rate-determining step. Thus, truly de novo catalyst discovery must include these steps. Here we present such a method for discovering catalyst candidates for a specific reaction while simultaneously proposing a mechanism for the catalyzed reaction. We show that tertiary amines and phosphines are potential catalysts for the MBH reaction by screening 11 molecular templates representing common functional groups. The method relies on an automated reaction discovery workflow using meta-dynamics calculations. Combining this method for catalyst candidate discovery with our GA-based catalyst optimization method results in an algorithm for truly de novo catalyst discovery.     

Fe-P-O催化剂上甲烷氧化偶联反应强制振荡的研究

制备了可还原型甲烷氧化偶联反应催化剂ＦｅＰＯ,并在非稳态操作条件下,考察了浓度强制振荡操作对反应的强化作用,并对该体系催化剂进行了ＸＲＤ表征．结果表明,与稳态相比,非稳态下周期循环进料操作能够明显改善催化反应性能;催化剂在反应过程中有新的物相生成,并对甲烷活化产生较大的影响．     

Methanol aided synthesis of PdNPs decorated on montmorillonite K 10 and its implication in Suzuki Miyaura type cross coupling reaction under base free condition

An efficient catalyst PdNPs decorated on Montmorillonite K 10 is prepared by simply stirring Pd(OAc)₂ in methanol at room temperature without using any external reducing agent. The catalyst shows excellent activity for Suzuki Miyaura type cross coupling reaction between aryl diazonium salt and arylboronic acid under ligand and base free reaction conditions within short reaction time. The main advantage of this methodology is the easy synthesis of heterogeneous PdNPs @ Mont K 10 catalyst in a mild condition without using any reducing agent or additive and the catalyst is very efficient for biaryl synthesis. The catalyst is well characterized by SEM, EDX, TEM, BET, Powder XRD, TGA, DSC etc. The reaction pathway is greener with aqueous reaction medium, base free reaction condition, room temperature and reusable heterogeneous catalyst.     

固相反应法制备Pt-Ru/C催化剂对乙醇氧化的电催化活性研究

0引言近年来,直接甲醇燃料电池(DMFC)由于其燃料来源丰富、价格低廉、甲醇携带和储存安全方便等独特的优越性而越来越受到重视[1]。但是甲醇具有一定的毒性,因此要想实现DMFC在诸如手机、笔记本电脑以及电动车等可移动电源领域的应用,必须探索新的液体燃料以替代有毒性的甲醇。     

腐植酸负载Pd/Ni双金属催化剂对Heck反应催化性能的研究

制备了腐植酸负载Pd/Ni双金属催化剂, 该催化剂能够成功催化溴苯与丙烯酸、苯乙烯等乙烯基化合物的Heck反应, 产率均在85%以上; 催化剂能够不同程度地重复使用, 在催化溴苯与丙烯酸反应中, 催化剂重复使用3次后仍可得到42.9%的产率, 而在催化溴苯与苯乙烯反应中, 催化剂重复使用7次后也可得到26.7%的产率; 并且对不同取代基芳基卤与丙烯酸的反应也有很好的催化活性.     

PRODUCTION OF LIGHT OLEFINS FROM CO_2 HYDROGENATION OVER Fe/SILICALITE-2 CATALYST Ⅳ. PERFORMANCE OF THE K-Fe-Mno/Si-2 CATALYST

IntroductionInordertodevelopanewcatalystwithbCttercarelyticedivityforseleCtiveproductionoflightolefinsfromCOZhydrogenation,asilicalite-2(St-2)zeolitesupportedFecatalystpromotedbyalkalimetalandMnOadditiveshasbeenacquiredwithmorethan68%oflightolefinselectiv…     

PRODUCTION OF LIGHT OLEFINS FROM CO2 HYDROGENATION OVER Fe/SILICALITE-2 CATALYST IV. PERFORMANCE OF THE K-Fe-MnO/Si-2 CATALYST

A new K-Fe-MnO/Si-2 catalyst has been developed for CO2 hydrogenation, which exhibits a fascinating reaction activity and light olefin selectivity for CO2 hydrogenation. Over the catalyst, it is observed that olefin selectivity increases apparently with reaction temperature and/or GHSV, while decreases when reaction pressure is up. Furthermore, the catalyst exhibits a better stability for CO2 hydrogenation. However, coke deposited on catalyst surface is formed at the beginning of the reaction period and then reached a stable state during CO2 hydrogenation. Generally, the K-Fe-MnO/Si-2 catalyst can be regenerated for CO2 hydrogenation, the same selectivity of C2=-C4=alkenes is regained without any decrease in catalyst activity with time on stream.     

Preparation of p—1,1,3,3—Tetramethylbutylphenol by Using Nafion—H Catalyst

p-1,1,3,3-Tetramethylbutylphenol was prepared by the alkylation of the phenol with Nafion catalyst in extremely high yield. Various reaction conditions were investigated, including the reaction temperature,reaction time, ratio of the starting material, amount of the Nafion catalyst and the recycle times of the catalyst.     

木质素负载钯催化剂的制备及对Heck反应的催化性能

以天然木质素和PdC l2为原料,合成了木质素负载钯催化剂,用IR、XPS、TG、DTA等对其进行了表征.研究表明,该催化剂在空气氛围中能催化丙烯酸与芳基碘的Heck反应,并有一定的重复使用性能.     

脂肪醇聚氧乙烯醚催化干法制备阳离子淀粉

阳离子淀粉是淀粉与阳离子试剂反应制得的一类很重要的淀粉衍生物。已广泛用于造纸、纺织、食品、油田、粘合剂、化妆品和污水处理等行业 [1 ,2 ]。阳离子淀粉传统的制备方法是溶液法 ,因反应时间长、溶剂消耗量大、产品成本高、对环境污染严重等 ,从而使产品的开发和应用受到限制。自 Caesar等 [3,4 ]发现干法制备阳离子淀粉的方法以来 ,受到了变性淀粉研究工作者的重视。在用 Na OH作催化剂 ,干法制备季铵型阳离子淀粉方面 ,国内也做了许多研究工作 ,取得了许多研究成果 [5～ 7]。岳世泰等 [8]也报道了用电磁干法制备阳离子淀粉的研究成…     

壳聚糖席夫碱钯催化碘代苯与丙烯酸乙酯反应

以水杨醛与壳聚糖反应制得的壳聚糖席夫碱配体再与PdCl2反应制得了壳聚糖席夫碱钯催化剂。研究了该催化剂对碘代苯(PhI)与丙烯酸乙酯(EA)偶联生成反式肉桂酸乙酯反应的催化性能。考察了原料比、缚酸剂种类及其用量、反应温度、溶剂、催化剂用量、反应时间等因素对该反应的影响,确定了该催化反应的最佳反应条件。该催化剂经过滤分离、溶剂洗涤,循环使用4次仍有较高的催化活性。     

钼酸胺催化剂对煤-油共处理反应性的影响

用共振搅拌反应器研究了钼酸胺催化剂对煤-油共处理中煤总转化率及产物的影响。研究表明，低温时(390 ℃)，催化剂能促进前沥青烯向小分子苯可溶物转化；高温时(480℃)，有催化剂时煤的转化率低于无催化剂时煤的转化率，而且在产物中苯可溶物产率与前沥青烯产率全部减少，说明产物发生了缩聚反应。在高温时(390 ℃)随反应时间的延长，煤转化率下降，同时在产物中苯可溶物产率与前沥青烯产率呈下降趋势。反应温度越高，反应时间越长，缩聚越严重。反应体系有供氢溶剂不能抑制缩聚反应。     

Silica-supported boric acid with ionic liquid: a novel recyclable catalytic system for one-pot three-component Mannich reaction

A rapid and efficient silica-supported boric acid/ionic liquid ([bmim][PF?]), catalyzed, one-pot three-component Mannich reaction has been carried out to synthesize β-amino carbonyl compounds at room temperature. The reaction afforded desired products in excellent yields with moderate to good diastereoselectivity. The method provides a novel modification of three-component Mannich reaction in terms of mild reaction conditions, clean reaction profiles, low amount of catalyst, recyclability of catalyst and a simple workup procedure. The present report first time describes the preparation of H?BO?-SiO? catalyst and its use with [bmim][PF?], to synthesize Mannich products. The catalyst can be reused at least seven times.     

Condensation reaction of 3-(methacryloxypropyl)-trimethoxysilane and diisobutylsilanediol in non-hydrolytic sol-gel process

The condensation reaction of 3-methacryloxypropyl-trimethoxysilane (MPTS) and diisobutylsilanediol (DIBSD) in a non-hydrolytic sol-gel process was investigated in terms of the reaction time and the catalyst amount for fabrication of inorganic-organic hybrid materials. The degree of condensation, which was characterized by ²⁹Si NMR, ¹H NMR and Abbe refractometry, increases with increased the reaction time and greater catalyst amount. However, a the large catalyst amount breaks the methacryl group during the condensation reaction. Thus, the reaction time and the catalyst amount were optimized to synthesize the condensed methacryl oligosiloxanes.     

Design and synthesis of the honeycomb PtSnNa/ZSM-5 monolithic catalyst for propane dehydrogenation

A novel PtSnNa/ZSM-5 monolithic catalyst was designed and synthesized for the propane dehydrogenation reaction, which was a significant transformation in industry. Experimental results showed that although the propane conversion and the propylene selectivity gradually fell down along with the reaction time, the descent speed of the PtSnNa/ZSM-5 monolithic catalyst was slower than that of the granule catalyst and the propane conversion and propylene selectivity of the reaction with monolithic catalyst still remained at a high level after 12 hr. The monolithic catalyst had regular pore structure that facilitated the separation of the product from the catalyst and reduced the limitation on internal and external diffusion and mass transfer, and led to the high catalytic activity and stability. The catalyst could be easily fabricated and was of highly industrial application potential.     

Silica‐supported terpyridine palladium(II) complex as an efficient and reusable catalyst for Heck and Suzuki cross‐coupling reactions

Silica‐supported terpyridine palladium(II) was prepared and used as an effective and recyclable catalyst in Mizoroki–Heck and Suzuki–Miyaura coupling reactions. The catalyst was very effective for the Mizoroki–Heck reaction of aryl halides with olefins and conversion was in most cases excellent. The catalyst showed good thermal stability (up to 230 °C) and could be recovered and reused for four reaction cycles. The Suzuki coupling of aryl iodides with aryl boronic acids in the presence of the catalyst was also investigated and the reaction proceeded with a short reaction time and excellent conversion. Copyright © 2013 John Wiley & Sons, Ltd.