分子催化最新文献_第7页

High temperature treated Pt/Sn ZnAl2O4 catalysts 高温处理Pt/SnZnAl2O4催化剂

Journal of Molecular Catalysis Pub Date : 1994-09-27 DOI: 10.1016/0304-5102(94)00095-6

P. Bosch , M.A. Valenzuela , B. Zapata , D. Acosta , G. Aguilar-Ríos , C. Maldonado , I. Schifter

引用次数: 20

Human placental alkaline phosphatase covalently immobilized on a cross-flow microfiltration polyvinylidene difluoride membrane. Part I. Physicochemical effectors 人胎盘碱性磷酸酶在交叉流微滤聚偏二氟乙烯膜上的共价固定化。第一部分:物理化学效应物

Journal of Molecular Catalysis Pub Date : 1994-09-27 DOI: 10.1016/0304-5102(94)00078-6

M.G. Roig , J.F. Bello , S. Rodriguez , J.M. Cachaza , J.F. Kennedy

引用次数: 2

Human placental alkaline phosphatase covalently immobilised on a cross-flow microfiltration polyvinylidene difluoride membrane Part II. Activity vs. [substrate] kinetic behaviour 人胎盘碱性磷酸酶在交叉流微滤聚偏二氟乙烯膜上的共价固定化。活性与[底物]动力学行为

Journal of Molecular Catalysis Pub Date : 1994-09-27 DOI: 10.1016/0304-5102(94)00079-4

M.G. Roig , J.F. Bello , S. Rodriguez , J.M. Cachaza , J.F. Kennedy

引用次数: 1

Comparison of reactivity of alkene epoxidation with intact cells and cell-free extracts of Methylosinus trichosporium OB3b 完整细胞和无细胞提取液对三磷酸甲藻OB3b烯烃环氧化反应活性的比较

Journal of Molecular Catalysis Pub Date : 1994-09-27 DOI: 10.1016/0304-5102(94)00089-1

Daisuke Sugimori, Ichiro Okura

{"title":"Comparison of reactivity of alkene epoxidation with intact cells and cell-free extracts of Methylosinus trichosporium OB3b","authors":"Daisuke Sugimori, Ichiro Okura","doi":"10.1016/0304-5102(94)00089-1","DOIUrl":"10.1016/0304-5102(94)00089-1","url":null,"abstract":"<div>Kinetic studies of a series of alkene epoxidations (ethylene, propylene and 1-butene) with intact cells and cell-free extracts of Methylosinus trichosporium OB3b were carried out. For the epoxidation with intact cells, Vmax values were independent of the type of alkenes. Km values, however, were remarkably different, and the order was ethylene < propylene < 1-butene. The results suggest that the reactivity of alkene epoxidation with intact cells of M. trichosporium OB3b strongly depends on the affinity of alkene and methane monooxygenase. For cell-free extracts, Vmax values for ethylene and propylene were almost the same. Vmax value for 1-butene was extremely small. Kmax values were remarkably different, and the order was ethylene < propylene < 1-butene. On the comparison of intact cells and cell-free extracts of M. trichosporium OB3b, the Kmax value of ethylene with intact cells was much smaller than that with cell-free extracts, indicating that ethylene is more easily incorporated into the cells. On the other hand, propylene and 1-butene are not easily incorporated on comparison of the Kmax values of intact cells with those of the cell-free extracts. These results indicate that the cell membrane may act to avoid higher alkenes.</div>","PeriodicalId":16567,"journal":{"name":"Journal of Molecular Catalysis","volume":"93 1","pages":"Pages 119-124"},"PeriodicalIF":0.0,"publicationDate":"1994-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-5102(94)00089-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76576181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Subnanometer nickel clusters in complex reducing agents 复合还原剂中的亚纳米镍团簇

Journal of Molecular Catalysis Pub Date : 1994-09-27 DOI: 10.1016/0304-5102(94)00100-6

Pierre Gallezot , Christiane Leclercq , Yves Fort , Paul Caubére

引用次数: 19

Structural study of TiIV exchanged K10-montmorillonite by XRD, EXAFS and XANES 用XRD、EXAFS和XANES研究TiIV交换k10 -蒙脱土的结构

Journal of Molecular Catalysis Pub Date : 1994-09-13 DOI: 10.1016/0304-5102(94)00075-1

M.C. Sanchez , J. García , J.A. Mayoral , J. Blasco , M.G. Proietti

引用次数: 3

Phase transfer catalysis — selected problems and applications 相转移催化的选择问题和应用

Journal of Molecular Catalysis Pub Date : 1994-09-13 DOI: 10.1016/0304-5102(94)80005-7

L.Hevesi Namur

引用次数: 0

Addition of tetrachloromethane to cis-cycloalkenes in the presence of transition metal complexes 在过渡金属配合物的存在下，四氯甲烷加成到顺环烯烃

Journal of Molecular Catalysis Pub Date : 1994-09-13 DOI: 10.1016/0304-5102(94)00080-8

Reg Davis , Krystyna Stephens , Milan Hájek

{"title":"Addition of tetrachloromethane to cis-cycloalkenes in the presence of transition metal complexes","authors":"Reg Davis , Krystyna Stephens , Milan Hájek","doi":"10.1016/0304-5102(94)00080-8","DOIUrl":"10.1016/0304-5102(94)00080-8","url":null,"abstract":"<div>Reactivity, regioselectivity and stereoselectivity of the addition reaction between tetrachloromethane and C5 to C10 cycloalkenes in the presence of copper, ruthenium, molybdenum, cobalt and iron complexes as catalysts and dibenzoyl peroxide as an initiator have been examined in the temperature range 22 to 80°C. Relative reactivities of the cycloalkenes decreased in sequence C8>C5>C7>C6>C10. These rates were not strongly affected by the catalysts indicating that the reactivities of cycloalkenes are mainly controlled by I-strain in the cycloalkene molecule. Transannular addition was observed in the reactions of cis-cyclooctene and cis-cyclodecene. The ratio of transannular to vicinal addition was significantly lowered by [RuCl2(PPh3)3] and [CuCl(NHEt2)2], in comparison with dibenzoyl peroxide. A strong catalyst effect on the stereoselectivity of the addition reaction of cyclohexene was also recorded. The trans:cis isomer ratio of the adduct was significantly affected by ruthenium catalysts and, to lesser extent, by copper, molybdenum, cobalt and iron catalysts. The catalyst effect on regioselectivity and stereoselectivity strongly support a non-chain mechanism involving coordination of reactants and product formation at the metal centre in contrast to the classical initiation of chain reactions by organic peroxides.</div>","PeriodicalId":16567,"journal":{"name":"Journal of Molecular Catalysis","volume":"92 3","pages":"Pages 269-276"},"PeriodicalIF":0.0,"publicationDate":"1994-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-5102(94)00080-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76986890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Homogeneous catalytic hydrogenation of olefins by use of RhH2(Ph2N3) (PPh3)2 in dimethyl sulfoxide 用RhH2(Ph2N3) (PPh3)2在二甲亚砜中催化烯烃均相加氢反应

Journal of Molecular Catalysis Pub Date : 1994-09-13 DOI: 10.1016/0304-5102(94)00085-9

Noriyuki Kameda, Reiko Igarashi

引用次数: 1

Oxidative dehydrogenation of n-butane on zinc-chromium ferrite catalysts 锌铬铁氧体催化剂上正丁烷氧化脱氢反应的研究

Journal of Molecular Catalysis Pub Date : 1994-09-13 DOI: 10.1016/0304-5102(94)00071-9

H. Armendariz , J.A. Toledo , G. Aguilar-Rios , M.A. Valenzuela , P. Salas , A. Cabral , H. Jimenez , I. Schifter

{"title":"Oxidative dehydrogenation of n-butane on zinc-chromium ferrite catalysts","authors":"H. Armendariz , J.A. Toledo , G. Aguilar-Rios , M.A. Valenzuela , P. Salas , A. Cabral , H. Jimenez , I. Schifter","doi":"10.1016/0304-5102(94)00071-9","DOIUrl":"10.1016/0304-5102(94)00071-9","url":null,"abstract":"<div>The role of chromium as a promoter of butadiene selectivity in n-butane oxidative dehydrogenation on ZnCrxFe2-xO4 (0<x<1.09) catalysts was studied. Catalysts have a spinel structure with Cr3+ replacing Fe3+ in octahedral sites. Mössbauer spectroscopy studies showed that the substitution of iron by chromium modifies the electron density of the iron nuclei in the ZnFe2O4 structure. Iron nuclei showed the lowest electron density for x=0.5–0.6, hence the electron density of oxygen in FeO bond has to be enhanced. n-Butane oxidative dehydrogenation also showed a maximum in butadiene selectivity at x=0.5–0.6. These results suggest that chromium increases butadiene and CO2 selectivities, with simultaneous decrease of butenes and cracking products explained by an enhancement of the lattice oxygen basicity, which promotes the acid-base type dissociation of the CH bond during butene activation.</div>","PeriodicalId":16567,"journal":{"name":"Journal of Molecular Catalysis","volume":"92 3","pages":"Pages 325-332"},"PeriodicalIF":0.0,"publicationDate":"1994-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-5102(94)00071-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89523287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13