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1.
 采用TiCl4气固相同晶取代法制得的Ti-ZSM-5作催化剂,对H2O2氧化苯乙烯反应的宏观动力学进行了研究,考察了催化剂、苯乙烯和H2O2用量及反应温度对苯乙烯氧化反应速率的影响.结果表明,催化剂Ti-ZSM-5和底物苯乙烯对苯乙烯氧化反应速率的贡献均为一级,而H2O2为1/2级;苯乙烯氧化反应的表观活化能Ea=48.14kJ/mol.当以丙酮为溶剂,在n(PhCH∶CH2)/n(H2O2)=7.91,催化剂用量为20g/L,反应温度为343K的条件下,反应360min时,苯乙醛选择性和H2O2利用率分别可达91.9%和88.6%.  相似文献   

2.
Fe/MnO-ZnZSM-5双功能催化剂上合成气直接转化为芳烃的反应   总被引:4,自引:0,他引:4  
 探讨了Fe/MnO-ZnZSM-5(n(SiO2)/n(Al2O3)=50)双功能催化剂上合成气直接转化为芳烃的反应,考察了反应温度和Zn载量对CO转化率及芳烃选择性的影响.结果表明,Fe/MnO-ZnZSM-5具有良好的合成气芳构化性能,在V(CO)∶V(H2)∶V(Ar)=3∶6∶1,SV=1600h-1,p=1.1MPa,T=543K的条件下,CO转化率可达到98.1%,芳烃产物选择性可高达53.1%.催化剂经60h运转后,CO转化率仅降低0.5%,显示了良好的稳定性和应用前景.  相似文献   

3.
 研究了不同助剂促进的负载型Pd-Se/H4SiW12O40/SiO2催化剂对乙烯直接氧化制乙酸反应的影响.采用固定床微反装置评价了催化剂的性能,并采用C2H4和O2吸附量测定、吸附C2H4的TPD-MS和TPSR-MS等技术对催化剂进行了表征.结果表明,以SiO2为载体,以硅钨酸为助剂,Pd-Se-Na-Ru组成的催化剂体系其催化性能比文献报道的结果明显提高.在原料气配比n(C2H4)∶n(N2)∶n(O2)∶n(H2O)=55∶14∶9∶22,反应物空速GHSV=3844h-1,反应压力p=1.4MPa,反应温度θ=155℃条件下,乙烯的转化率和乙酸的选择性分别为8.0%和87.4%,乙酸的单程时空产率达372.0g/(L·h).吸附量测定表明,吸附在催化剂表面上的C2H4/O2比值高对于提高乙酸的选择性是有利的.  相似文献   

4.
硒催化CO/H2O选择性还原间二硝基苯制间硝基苯胺   总被引:5,自引:0,他引:5  
 采用硒作催化剂,乙酸钠为助催化剂,用CO/H2O对间二硝基苯进行部分还原制备了间硝基苯胺. 考察了时间、CO压力、温度、催化剂用量、溶剂和水量等因素对反应的影响. 以四氢呋喃作溶剂,使用摩尔量为间二硝基苯20倍的水和4%的硒,在160 ℃和CO压力1 MPa下反应3 h,间二硝基苯转化率可达100%,间硝基苯胺的选择性和收率均为95.7%.  相似文献   

5.
Mo/La-Co-O催化剂上甲烷选择氧化制甲醇反应   总被引:6,自引:0,他引:6  
 制备了一系列Mo/La-Co-O催化剂,考察了催化剂对甲烷选择氧化制甲醇反应的催化性能,并用BET,XRD,LRS,H2-TPR和XPS等技术研究了催化剂的结构和性质.结果表明,在n(CH4)∶n(O2)∶n(N2)=10∶1∶1,SV=14.4L/(g·h),p=4.2MPa和θ=420℃的反应条件下,7%Mo/La-Co-O催化剂表现出较好的催化性能,甲醇选择性为60%,甲醇收率为6.7%.Mo负载于La-Co-O上以后,Mo-O物种以无定形的状态存在于La-Co-O表面,并与La-Co-O发生相互作用.Mo的负载量影响Mo-O物种的结构及催化剂的性质.催化剂的还原性和表面O-/O2-比影响催化剂上甲烷选择氧化制甲醇反应的性能.  相似文献   

6.
 用等体积浸渍法制备了ZrO2-SiO2(ZrSiO)表面复合氧化物负载的Cu-Ni催化剂,并用IR,TPR,TPD及微反技术考察了K2O助剂对CO2和CH3OH在Cu-Ni/ZrSiO催化剂表面上的吸附及合成碳酸二甲酯(DMC)反应性能的影响.结果表明:加入K2O助剂使CO2在催化剂表面上的吸附增强,当n(K)/n(Cu+Ni)=15%时,CO2在催化剂表面上吸附后生成K2CO3;CH3OH在催化剂表面上的解离吸附态(CH3O-和H+)的吸附减弱;CO2和CH3OH在Cu-Ni/ZrSiO催化剂表面上反应的主要产物为DMC,H2O,CO和CH2O;随着K2O助剂的加入,反应转化率及DMC选择性提高,副产物(CO和CH2O)的选择性下降.根据实验结果,探讨了K2O对催化剂表面活性中心电荷分布的影响.  相似文献   

7.
温控相分离催化三聚丙烯氢甲酰化反应的研究   总被引:3,自引:2,他引:3  
 首次将温控相分离催化概念应用于三聚丙烯氢甲酰化反应中.系统研究了各种反应条件对三聚丙烯氢甲酰化反应的影响,考察了催化剂的循环使用效果.以RhCl3·3H2O为催化剂前体,以P[p-C6H4O(CH2CH2O)nH]3为配体,在V(H2)/V(CO)=1,p=6MPa,θ=130℃的反应条件下,三聚丙烯氢甲酰化反应的转化率和醛收率可分别达到76.3%和72.1%.催化剂循环使用三次,仍有较高的催化活性.  相似文献   

8.
正丁烷氧化制顺酐流化床催化剂的性能   总被引:1,自引:0,他引:1  
许文  薛常海 《催化学报》2002,23(3):199-202
 考察了前驱体制备过程中水合肼/五氧化二钒摩尔比(以下简记\r\n为n(N2H4)/n(V2O5))对催化剂性能的影响.由较高的n(N2H4)\r\n/n(V2O5)比制得的催化剂,其(VO)2P2O7相含量较多,正丁烷转化\r\n率较高.随着n(N2H4)/n(V2O5)比的减小,δ-VOPO4相的含量逐\r\n渐增多,正丁烷转化率随之升高;而顺酐选择性开始时升高,达到最大\r\n值后逐渐降低.在n(N2H4)/n(V2O5)=0.34时制备的催化剂最佳\r\n,在丁烷浓度为4.0%、空速为500h-1及反应温度为420℃的反应条件\r\n下,顺酐收率可达49.74%.本文中细粒床催化剂有较大的操作弹性.  相似文献   

9.
 在固定床积分反应器中,对Fe-Mn催化剂上F-T合成反应的初期反应性能进行了一系列条件实验,考察了在不同温度、压力、原料气H2/CO比和空速下催化剂的催化性能.结果表明,该催化剂运行200h后,仍显示出较高的催化活性和稳定性,对低碳烯烃和C5+烃具有较高的选择性,且C5+烃的时空收率较高.在n(H2)/n(CO)=1,GHSV=6000h-1,p=2.02MPa和θ=300℃的条件下,CO转化率可达74.1%,总有效烃(C=2~4+C5+)的选择性可达88.6%,甲烷选择性为6.7%,C5+烃的时空收率为0.54g/(ml·h).  相似文献   

10.
异戊二烯催化脱氢环氧化的研究   总被引:1,自引:0,他引:1  
 合成了钼-乙酰丙酮配合物,并进行了表征,确定了其组成为M\r\noO2(acac)2.以MoO2(acac)2为催化剂,以过氧化氢为氧化剂,对\r\n异戊二烯一步脱氢环氧化制3-甲基呋喃反应进行了研究.考察了反应\r\n条件(催化剂用量、反应底物之比、温度、时间、溶剂和助剂等)对该\r\n反应的影响.结果表明,在n(cat)∶n(CH2∶C(CH3)CH∶CH2)∶\r\nn(H2O2)=1∶100∶100,θ=40℃,t=6h的反应条件下,异戊二烯\r\n转化率为70.8%,3-甲基呋喃选择性为54.8%.提出了异戊二烯脱\r\n氢环氧化可能的反应机理.  相似文献   

11.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

12.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

13.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

14.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.  相似文献   

17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.  相似文献   

18.
19.
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).  相似文献   

20.
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.  相似文献   

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