Journal of Molecular Catalysis Pub Date : 1994-08-12 DOI: 10.1016/0304-5102(94)00057-3

Raphael C. Mordi , Roy Fields, John Dwyer

引用次数: 3

Strontium hydroxyapatites: Catalytic properties in the oxidative dehydrogenation of methane to carbon oxides and hydrogen 锶羟基磷灰石:甲烷氧化脱氢生成碳氧化物和氢的催化性能

Journal of Molecular Catalysis Pub Date : 1994-08-12 DOI: 10.1016/0304-5102(94)00058-1

Yasuyuki Matsumura , Shigeru Sugiyama , Hiromu Hayashi , Naoya Shigemota , Kanako Saitoh , John B. Moffat

引用次数: 32

Study of cobalt complexes as catalysts in the decomposition of hydrogen peroxide 钴配合物催化过氧化氢分解的研究

Journal of Molecular Catalysis Pub Date : 1994-08-12 DOI: 10.1016/0304-5102(94)00063-8

R.V. Prasad, N.V. Thakkar

{"title":"Study of cobalt complexes as catalysts in the decomposition of hydrogen peroxide","authors":"R.V. Prasad, N.V. Thakkar","doi":"10.1016/0304-5102(94)00063-8","DOIUrl":"10.1016/0304-5102(94)00063-8","url":null,"abstract":"<div>The role of cobalt(II) and its complexes with 1-phenyl 1-hydrazonyl 2-oximinopropanedione (HPHOPD) as homogeneous and heterogeneous catalysts in the decomposition of hydrogen peroxide has been investigated by measuring evolution of oxygen at different time intervals in the temperature range 35–60°C. Enhanced activity is observed with Co(PHOPD)2 used as heterogeneous catalyst and with cobalt:HPHOPD (1:1) complex heterogenized by adsorption on alumina, while in case of solutions of cobalt(II) chloride and cobalt:HPHOPD (1:1), used as homogeneous catalysts, the activity is comparatively low and negligible respectively. The reaction rate, in general, is found to increase with increase in temperature and quantity of the catalyst. Various thermodynamic parameters have been calculated. The adduct formation with a heterocyclic base like pyridine, 3-methyl pyridine, chloro pyridine or quinoline is found to inhibit the catalytic activity of Co(PHOPD)2. The probable reaction mechanisms have been suggested for Co(PHOPD)2 and alumina-CoII-HPHOPD as catalysts.</div>","PeriodicalId":16567,"journal":{"name":"Journal of Molecular Catalysis","volume":"92 1","pages":"Pages 9-20"},"PeriodicalIF":0.0,"publicationDate":"1994-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-5102(94)00063-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86649679","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: 32

Study of the reactivity of ClCo(PPh3)3 ClCo(PPh3)3的反应性研究

Journal of Molecular Catalysis Pub Date : 1994-08-12 DOI: 10.1016/0304-5102(94)85005-4

Hae-Youn Rhyoo, Bun Yeoul Lee, Hye Kyung Bae Yu, Young Keun Chung

{"title":"Study of the reactivity of ClCo(PPh3)3","authors":"Hae-Youn Rhyoo, Bun Yeoul Lee, Hye Kyung Bae Yu, Young Keun Chung","doi":"10.1016/0304-5102(94)85005-4","DOIUrl":"10.1016/0304-5102(94)85005-4","url":null,"abstract":"<div>The catalytic activity of ClCo(PPh3)3 in oligomerization of alkynes and reduction of carbonyl compounds has been investigated. Monosubstituted alkynes with an electron withdrawing group give quantitative yields of arene derivatives when reacted with 5 mol% of ClCo(PPh3)3. Cyclotrimerization of disubstituted alkynes with at least one electron withdrawing group requires the addition of NaBPh4. In the oligomerization of phenylacetylene, cyclotrimerization and linear dimerization are in competition. However, when the reaction is run in the presence of 1.2 equiv. of NaOMe at room temperature, only linear dimerization is observed. Diethyl allylpropargylmalonate also cyclodimerizes or codimerizes with diphenylacetylene by catalytic amount of ClCo(PPh3)3 in the presence of NaOEt. Reaction of a variety of carbonyl compounds with 5 mol% of ClCo(PPh3)3 in i-propanol leads to the reduction of the compounds to the corresponding alcohols. The reaction requires the addition of NaH which produces (i-PrO)Na in situ. The role of alkoxides or NaBPh4 in ClCo(PPh3)3 catalyzed oligomerization of alkynes or reduction of carbonyl compounds is discussed.</div>","PeriodicalId":16567,"journal":{"name":"Journal of Molecular Catalysis","volume":"92 1","pages":"Pages 41-49"},"PeriodicalIF":0.0,"publicationDate":"1994-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-5102(94)85005-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79280676","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: 20

Chelate control in the nickel-complex catalysed homogeneous oligomerization of ethylene 镍络合物催化乙烯均匀寡聚反应的螯合控制

Journal of Molecular Catalysis Pub Date : 1994-08-12 DOI: 10.1016/0304-5102(94)00050-6

Wilhelm Keim, Rolf P. Schulz

引用次数: 81

Catalytic and structural properties of ruthenium bimetallic catalysts: Preparation and characterization 钌双金属催化剂的催化和结构性能:制备和表征

Journal of Molecular Catalysis Pub Date : 1994-08-12 DOI: 10.1016/0304-5102(94)85006-2

Bernard Coq ∗ , Eleanor Crabb , Mayukh Warawdekar , Geoffrey C. Bond , Joop C. Slaa , Signorino Galvagno , Lucina Mercadante , Joaquin Garcia Ruiz , Maria Conception Sanchez Sierra

{"title":"Catalytic and structural properties of ruthenium bimetallic catalysts: Preparation and characterization","authors":"Bernard Coq ∗ , Eleanor Crabb , Mayukh Warawdekar , Geoffrey C. Bond , Joop C. Slaa , Signorino Galvagno , Lucina Mercadante , Joaquin Garcia Ruiz , Maria Conception Sanchez Sierra","doi":"10.1016/0304-5102(94)85006-2","DOIUrl":"10.1016/0304-5102(94)85006-2","url":null,"abstract":"<div>In the framework of an EC Stimulation Action Programme, alumina-supported mono- and bimetallic Ru, RuGe, RuSn and RuPb catalysts have been prepared from both organic and inorganic precursors. Herein are presented some basic properties of these materials obtained by TPR and TPO experiments, H2 and CO chemisorption, TEM examination, XPS and EXAFS studies. The use of organic precursors led to very small Ru particles, with a coordination number between Ru atoms of 4.35 (Ru0-Ru0+Ru0-Ruδ+). The size of the metallic particles was not modified by adding Ge, Sn or Pb by the controlled surface reaction technique. In very small aggregates, some Ru atoms (10–15%) remained partially oxidised even after reduction at 623 K in flowing hydrogen. During the coimpregnation of alumina with inorganic precursors, the modifier played the role of a nucleation center for Ru, thus allowing small particles to be formed. We believe that CO could modify the surface composition of small bimetallic RuGe particles during the chemisorption.</div>","PeriodicalId":16567,"journal":{"name":"Journal of Molecular Catalysis","volume":"92 1","pages":"Pages 107-121"},"PeriodicalIF":0.0,"publicationDate":"1994-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-5102(94)85006-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84373200","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: 40

Molecular orbital study of the gas phase reaction of NaxBi4 clusters with HCl (x = 1,2) NaxBi4簇与HCl (x = 1,2)气相反应的分子轨道研究

Journal of Molecular Catalysis Pub Date : 1994-08-12 DOI: 10.1016/0304-5102(94)00060-3

R.Pis Diez, M.P. Iñiguez

引用次数: 0

Catalysis of phosphine-coordinated rhodium(I) complexes for 2-propanol dehydrogenation 膦配位铑配合物对2-丙醇脱氢的催化作用

Journal of Molecular Catalysis Pub Date : 1994-08-12 DOI: 10.1016/0304-5102(94)00033-6

Toshiaki Matsubara , Yasukazu Saito

引用次数: 19

Is metallic palladium formed in Wacker oxidation of alkenes? 金属钯是在烯烃的瓦克氧化中形成的吗?

Journal of Molecular Catalysis Pub Date : 1994-07-29 DOI: 10.1016/0304-5102(94)00043-3

Milan Hronec, Zuzana Cvengrošová, Štefan Holotík

{"title":"Is metallic palladium formed in Wacker oxidation of alkenes?","authors":"Milan Hronec, Zuzana Cvengrošová, Štefan Holotík","doi":"10.1016/0304-5102(94)00043-3","DOIUrl":"10.1016/0304-5102(94)00043-3","url":null,"abstract":"<div>The oxidation of cyclohexene with molecular oxygen catalyzed by solid Pd/C or PdII acetate—hydroquinone—iron phthalocyanine gives cyclohexane, benzene and oxygenated products. Oxygen pressure and solvent used influence significantly the distribution of the products and at the pressure above 2 atm no cyclohexane is formed. Over Pd/C catalyst in the absence of oxygen, disproportionation to cyclohexane and benzene (the ratio is nearly 2:1) proceeds exclusively. Under comparable conditions 2-cyclohexenol is disproportionated to cyclohexanol and phenol and some of it rearranges to cyclohexanone. The explanation for the disproportionation of cyclohexene under the Wacker conditions is that Pd0 centres intermediately formed after stoichiometric oxidation of cyclohexene by PdII are not completely reoxidized, but depending on the reaction conditions, they can partly aggregate and then, similarly to metallic surfaces, dehydrogenate cyclohexene to benzene. The hydrogen species formed migrate on the palladium surface and hydrogenate cyclohexene or at sufficient oxygen pressure they are oxidized to water.</div>","PeriodicalId":16567,"journal":{"name":"Journal of Molecular Catalysis","volume":"91 3","pages":"Pages 343-352"},"PeriodicalIF":0.0,"publicationDate":"1994-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-5102(94)00043-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76374157","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: 6

14th North American meeting of the catalysis society 第14届北美催化学会会议

Journal of Molecular Catalysis Pub Date : 1994-07-29 DOI: 10.1016/0304-5102(94)00093-X

引用次数: 0

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