An Active and Stable Methanol Synthesis Catalyst for the Three－Phase Process

Methanolisoneofthemostimportantbasicfeedstockfortheorganicchemicalindustryandalsoisapotentialfuel.Althoughthetechnologyforthepro ductionofmethanolisgenerallyconsideredmature ,muchattentionisstillbeingpaidtotheimprovementsoftheprocess ,equipmentandcatalyst .Ascomparedwiththeexisting gas solidtwo phase process ,thethree phase (alsocalledtheslurryphaseorliquidphase) processhastheadvantagesofsimplerstructureofthereactor,moreuniformtemperaturedistributioninthereactor ,higherone throughconversionof…     

An Efficient Catalyst for the Direct Synthesis of N-Phenylpyrrolidine

N-Phenylpyrrolidine is an important N-heterocycle compound used in the fields of medicine, the material chemistry and the synthesis of fine chemicals1-3. There are a lot of methods to produce N-phenylpyrrolidine4-6. However, One of the most promising rout…     

A Novel Synthesis of N-Methyl-N-aryl Carbamates from Aromatic Amines and Dimethyl Carbonate Catalyzed by K2CO3／Bu4NBr

A facile synthesis of N-methyl-N-aryl carbamates from aromatic amines and dimethyl carbonate (DMC) has been achieved with high yields in the presence of potassium carbonate (K2CO3) and tetrabutylammonium bromide (Bu4NBr) under solvent-free conditions.     

Purification Influence of Synthesis Gas Derived from Methanol Cracking on the Performance of Cobalt Catalyst in Fischer-Tropsch Synthesis

1. Introduction Fischer-Tropsch synthesis (FTS) has gained in- dustrial attention for converting synthesis gas to high- boiling points waxes that can be further converted to sulfur-free motor fuels by hydrogenation or hydroc- racking as alternative resour…     

Study on Highly Active Catalysts and a Once—Through Process for Methanol Synthesis from Syngas

Highly active CNT-promoted co-precipitated Cu-ZnO-Al2O3 catalysts, symbolized as CuiZnj;Alfc-a;%CNTs, were prepared, and their catalytic activity for once-through methanol synthesis from syngas was investigated. The results illustrated that, under the reaction conditions (at 493 K, 5.0 MPa, the volume ratio of H2/CO/CO2/N2= 62/30/5/3, GHSV= 4000 h-1), the observed single-pass CO-conversion and methanol-STY over a Cu6Zn3Al1-12.5%CNTs catalyst reached 64% and 1210 mg/(h-g), which was about 68% and 66% higher than those (38% and 730 mg/(h-g)) over the corresponding CNT-free catalyst, Cu6Zn3Al1, respectively. The characteristic studies of the catalysts revealed that appropriate incorporation of a minor amount of the CNTs into the CuiZnjAlk brought about little change in the apparent activation energy of the methanol synthesis reaction, however, led to a considerable increase in the catalyst's active Cu surface area and pronouncedly enhanced the stationary-state concentration of active hydrogen-adspecies on     

A Novel Sul ded Mo/C Catalyst for Direct Vapor Phase Carbonylation of Methanol at Atmospheric Pressure

The direct carbonylation of methanol, without any halide in the feed as a promoter, is presented. A series of Mo catalysts supported on activated carbon, y-Al2O3 and SiO2 were prepared. The results show that the support greatly affects the Mo catalyst in the direct vapor-phase carbonylation of methanol, and activated carbon is the best supports of the investigated supports. In addition, the relationships between adsorptions of NH3 and CO and carbonylation of methanol were investigated. A novel sulfided Mo/C catalyst had high activity and selectivity for the vapor phase carbonylation of methanol to methyl acetate without the addition of a CH3I promoter to the feed. The reaction conditions were optimized at a reaction temperature of 573 K, a methanol concentration of 23 mol% and a carbon monoxide space velocity of 3,000 L/(kg-h). Under these optimal conditions a methanol conversion of 50%, carbonylation selectivity of 80 mol%, and space-time yield of 8.0 mol/(kg-h) were obtained. The active phase of this     

A New Process for Synthesis of Dimethyl Carbonate from Ethylene Carbonate and Methanol without any Catalyst under Supercritical Conditions

Dimethyl carbonate was synthesized by transesterification reaction between ethylene carbonate and methanol under supercritical conditions without any catalyst. Experimental results showed that the residence time and the molar ratio of methanol to ethylene carbonate all can affect the conversion of ethylene carbonate. When the molar ratio of methanol to ethylene carbonate was 8:1, 81.2% conversion can be achieved at 9.0 MPa and 250℃ after 8 h.     

Synthesis and herbicidal activities of pyridyl sulfonylureas： More convenient preparation process of phenyl pyrimidylcarbamates

Four 4-monosubstituted pyrimidine pyridyl sulfonylureas were synthesized from pyridinesulfonamide and phenyl pyrimidylcarbamate and screened for herbicidal activities. We also reported a convenient preparation process of phenyl pyrimidylcarbamates from pyrimidineamine and phenyl chloroformate.     

Convenient and One-pot Method for Synthesis of the Amino-methylene Bisphosphonic Acid Derivatives from Aldehydes

Bisphosphonic acids and their ester derivatives, carbon analogues of inorganic pyrophos- phate, are the most important organophosphorus compounds and exhibit unique physical and chemical properties in interaction with the alkaline earth cations or heavy m…     

Synthesis of Novel Anionic Receptors with （Thio）urea and Amide Binding Sites and the Recognition Properties for Anions

IntroductionSincemoreandmoreanionsplayanimportantroleinbiologicalandchemicalprocesses ,thedesignandsynthe sisofreceptorsforon lineandrealtimedetectionofbio logicallyimportantanions ,andforenvironmentalmonitor ingofharmfulanionpollutantshaveattractedparticularat tentioninsupramolecularchemistry .1Thebasicstrategyfortheconstructionofanion bindingreceptorsistoexploitthereceptorsthathaveelectrostatic ,2 hydrogenbonding ,3orLewisacidiccentralinteraction .4 Amongavarietyofnon covalentinteractions ,h…     

苯基脲与甲醇合成苯氨基甲酸甲酯的研究

采用苯基脲与甲醇反应合成了苯氨基甲酸甲酯,考察了不同催化剂、原料配比及反应工艺条件的影响,确定了适宜的合成条件,并根据产物分布对催化反应机理进行了初步探讨.结果表明,以PbO为催化剂,于140℃反应4h后,苯基脲转化率为95.2%,苯氨基甲酸甲酯收率为80.6%.     

苯胺与碳酸二甲酯反应合成苯氨基甲酸甲酯

 在系统研究PbO催化剂对苯胺与碳酸二甲酯反应合成苯氨基甲酸甲酯（MPC）的催化性能的基础上，考察了不同载体负载的PbO的催化性能，筛选出活性较高的SiO2载体．以SiO2为载体，考察了不同活性组分对MPC合成的催化性能，优选出了具有较高催化活性的In2O3／SiO2催化剂．在该催化剂的催化下，苯胺转化率可达75．98％，MPC选择性为78．24％．     

负载PbO催化剂对苯胺与碳酸二甲酯合成苯氨基甲酸甲酯的催化性能

 考察了几种负载PbO催化剂对苯胺(An)与碳酸二甲酯(DMC)反应合成苯氨基甲酸甲酯(MPC)的催化性能. 结果表明, PbO/SiO2对该反应表现出很高的催化活性. 当w(PbO)=3.6%, n(PbO)/n(An)=1%, n(DMC)/n(An)=5, θ=160 ℃和t=4 h时, MPC收率达到99.5%. PbO/SiO2容易从反应体系中分离,且可重复使用5次,催化活性基本保持不变,使用寿命较长.     

苯氨基甲酸甲酯分解催化剂Bi-Zn复合氧化物的制备及其催化性能

采用共沉淀法制备了一系列Bi-Zn复合氧化物催化剂并将其用于催化苯氨基甲酸甲酯(MPC)分解制备苯基异氰酸酯(PI).用热重、X射线衍射和傅里叶变换红外光谱考察了Bi/Zn摩尔比和焙烧温度对催化剂物相结构和表面性质的影响.结果表明,Zn的加入使Bi_2O_3由α晶相转变为活性更高的β晶相,500℃焙烧时Bi-Zn前驱体分解较为完全,析出Bi_2O_3粒子的同时伴生较多Bi_(7.65)Zn_(0.35)O_(11.83)晶相.在Bi/Zn摩尔比为2/1,焙烧温度为500℃条件下制得的催化剂活性最高,此时MPC转化率为86.O%,PI选择性为91.7%,优于单独使用Bi_2O_3时的催化性能.     

碳酸二甲酯胺解合成苯氨基甲酸甲酯催化研究

研究了Sn、Ti、Zn、Pb类型的催化剂对碳酸二甲酯与苯胺反应合成苯氨基甲酸甲酯(MPC)的催化性能，对活性较好的PbO催化剂作了比较详细的研究，发现在170℃，反应回流4h，PbO的用量为苯胺摩尔数的7．5％时，苯胺的转化率可以达到81％．对二元金属氧化物催化剂作了一定的考察，发现Pb2O4—ZnO复合催化剂的活性比单独使用Pb3O4或ZnO时高，显示出一定的增效作用．     

The Effect of Rare Earth on the Activity of Methanol Synthesis Catalyst

AlthoughtheCuO/ZnO/Al=O,cataIysthasbeenusedasasuccessfulmethan0lsynthesiscatalystfromCOhydrogenationformanyyears,itscatalyticactivityisnothighenoughf0rmethan0Isynthesisfr0mpureCO,hydrogenati0n.Manynewsynthesismethods,includingsol-gelco-precipitati0nmethodandultrasonicsynthesismeth0d,wereusedtopreparethemethanolsynthesiscatalyst"'.Intheliterature,manymetal0xidessuchasZrO,,Cr,O,,Ga,O,,Al,O,,SiO,andTiO,etc.wereaddedintocatalystt0improveitscatalyticactivityandmethanoIselectivity'~'.Howev…     

添加助剂的低铬Cu-Cr-Si催化剂和甲酸甲酯氢解制甲醇

通过对低铬Cu-Cr-Si催化剂以及添加了不同助剂的低铬Cu-Cr-Si催化剂用于甲酸甲酯氢解反应的性能研究，发现助剂B、Zr、Ca、Ba、Mg能够有效地提高低铬Cu-Cr-Si催化剂的活性。并采用TPR、XRD等手段对催化剂进行了表征。     

氧化锆负载氧化钌催化甲醇低温选择氧化合成甲酸甲酯的活性催化剂结构

 采用ZrO2负载的RuOx催化剂在低温(如373 K)下催化甲醇选择氧化合成甲酸甲酯,发现RuOx的结构可显著影响反应速率和产物选择性. 在相近的甲醇转化率下, RuO2-4物种的催化活性和对甲酸甲酯的选择性明显高于RuO2物种, 表明在ZrO2表面构筑高活性高选择性的RuO2-4结构有利于获得高的甲酸甲酯产率.     

铜基甲醇合成催化剂的失活研究

选用了两个化肥厂的失活甲醇合成催化剂,采用ＸＲＤ、ＳＥＭ、ＳＥＭ－ＥＤＳ、ＴＥＭ、ＸＰＳ、ＴＲＰ、ＣＯ－ＴＰＤ和化学吸附等方法对催化剂进行比较测试。结果表明,硫中毒、积炭、铜粒长大和杂质金属沉积等是造成甲醇合成催化剂失活的因素。由于某一种或几种因素都导致催化剂活性表面积的降低,对反应物ＣＯ吸附量减少,或造成催化剂对ＣＯ吸附能力的降低,从而降低合成甲醇反应的活性。硫中毒和铜粒长大是普遍存在的最主要因     

氟丙嘧草酯的合成新工艺

以2-氯-5-硝基苯甲酸甲酯为原料,经还原、缩合得2-氯-5-(乙氧羰基)氨基苯甲酸甲酯(3);3与3-氨基-4,4,4-三氟巴豆酸乙酯进行环合得脲嘧啶环中间体(4);4经甲基化、水解、酰化和缩合反应合成了氟丙嘧草酯,总收率55.2%,纯度99.1%。中间体和产物结构经1H NMR和EI-MS确证。