Piri Keşif Aracı

1

Hydrogenation of o-chloronitrobenzene over polymer-stabilized palladium–platinum bimetallic colloidal clusters

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Xinlin Yang , Hanfan Liu , Hao Zhong

Yıl :

1999

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Hydrogenation of o-chloronitrobenzene (o-CNB) has been studied in methanol at 303 K and atmospheric pressure over polyvinylpyrrolidone-stabilized palladium–platinum (PVP-Pd/Pt) bimetallic colloidal clusters. The catalytic properties for the hydrogenation of o-CNB to o-chloroaniline (o-CAN) are found to depend on the metal composition of the bimetallic clusters. All the bimetallic clusters are more active than both PVP-Pd and PVP-Pt monometallic clusters. The highest activity (1.81 mol H2/mol M s) is obtained when PVP-Pd/Pt (1/2) is used as catalyst. The best selectivity to o-CAN (77.5%) is achieved in PVP-Pd/Pt (1/3) catalytic system, which is much higher than those of PVP-Pt and PVP-Pd monometallic colloidal clusters. The addition of the metal cations to the system can considerably affect the catalytic properties of the bimetallic clusters. The modification behavior of metal cations also depends both on the composition of PVP-Pd/Pt bimetallic clusters and the nature of metal cations. For the PVP-Pd/Pt (1/3) bimetallic clusters, when introducing Cr3+ and Co2+, the high activity (0.96 and 1.03 mol H2/mol M s) and the better selectivity (91.5 and 91.4%) compared with those of the neat PVP-Pd/Pt (1/3) catalysts (1.03 mol H2/mol M s and 77.5%) are obtained, respectively.

DOI : 10.1016/S1381-1169(99)00128-4

Anahtar Kelimeler : Pd/Pt bimetallic colloid, Metal ion modifier, Hydrogenation, o-Chloronitrobenzene

Cilt: 147
Sayı: 1-2
Sayfa: 55-62
ISSN: 1381-1169

2

Metathesis of halogen-containing olefin over Re2O7/Al2O3 catalyst promoted with alkylmetal as a cocatalyst

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Tadashi Kawai , Seiji Uejima , Takehiko Suzuki , Tomokazu Iyoda

Yıl :

1998

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The 1-alkene containing bromide has been metathesized over Re2O7/Al2O3 catalyst promoted with alkylmetal as a cocatalyst to elucidate the effects of addition of alkylmetal and reaction conditions. The reaction was carried out using a continuous flow apparatus under atmospheric pressure. Various kinds of alkylmetal were employed as cocatalyst. By the addition of small amounts of tetraalkyltin, the activity increased greatly in the sequence of Bu-

DOI : 10.1016/S1381-1169(98)00088-0

Anahtar Kelimeler : Metathesis, Rheniau2013alumina catalyst (Re2O7/Al2O3 catalyst), Olefin containing halogen (halogenated olefin, functionalized olefin), Deactivation mechanism, Alkylmetal, Cocatalyst

Cilt: 133
Sayı: 1-2
Sayfa: 51-59
ISSN: 1381-1169

3

Hydrosilylation of aromatic nitriles promoted by solvated rhodium atom-derived catalysts

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Anna Maria Caporusso , Nicoletta Panziera , Paolo Pertici , Emanuela Pitzalis , Piero Salvadori , Giovanni Vitulli , Gianmario Martra

Yıl :

1999

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Rhodium metal particles, isolated as supported or unsupported powder starting from mesitylene solvated rhodium atoms, catalyse the hydrosilylation of aromatic nitriles to N,N-disilylamines in high conversion at 100°C. Different hydrosilanes (HSiMe3, HSi(OEt)3) can be employed. In the case of cinnamonitrile, the chemoselectivity of the reaction to 2-trimethylsilyl-3-phenylpropionitrile and (E)- and (Z)-1-di(trimethylsilyl)amino-3-phenyl-1-propene is strongly dependent on the reaction temperature. The commercial rhodium on γ-Al2O3 catalyst is considerably less active and selective than the analogous catalyst prepared via Metal Vapour Synthesis (MVS) probably owing to the different dimension and distribution of the metal particles in the two samples as shown by HRTEM analysis.

DOI : 10.1016/S1381-1169(99)00225-3

Anahtar Kelimeler : Rhodium nanoparticles, Hydrosilylation, Aromatic nitriles, Catalysis, N, N-Disilylamines

Cilt: 150
Sayı: 1-2
Sayfa: 275-285
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organometalik Kimya %100

4

1,3-Butadiene telomerization with methanol catalyzed by heterogenized palladium(II) complexes anchored to polymer-bound bis(diphenylphosphino)methane moieties

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Federica Benvenuti , Carlo Carlini , Mario Marchionna , Renata Patrini , Anna Maria Raspolli Galletti , Glauco Sbrana

Yıl :

1999

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The telomerization of 1,3-butadiene with methanol in the presence of heterogenized palladium(II) catalysts, obtained by anchoring the metal on both a styrene/divinylbenzene macroporous resin and a linear poly(styrene) functionalized with bis(diphenylphosphino)methane moieties, is reported. In particular, the activity and selectivity to telomers of the above catalytic systems is compared with the corresponding homogeneous counterpart and with those previously obtained with analogous heterogenized systems via polymer-bound 1,3-bis(diphenylphosphino)propane moieties. The effect of a methoxide promoter is also studied. Finally, the performances and metal leaching in solution of the above heterogenized catalysts are checked after several reaction cycles in order to verify their real heterogeneous character.

DOI : 10.1016/S1381-1169(98)00215-5

Anahtar Kelimeler : Telomerization, 1, 3-Butadiene, Methanol, Palladium(II) complexes, Phosphinated styrene/divinylbenzene resins, Heterogenized catalysts

Cilt: 139
Sayı: 2-3
Sayfa: 177-187
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

5

Editorial Board

Dergi Makalesi Open Access

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yıl :

2016

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Ek Bilgiler

Kaydet

DOI : 10.1016/S1381-1169(15)00311-8

Cilt: 412
Sayı: 0
Sayfa: iii-0
ISSN: 1381-1169

6

Zeolite-promoted selective mono-N-methylation of aniline with dimethyl carbonate

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Thirugnanasamy Esakkidurai , Kasi Pitchumani

Yıl :

2004

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Selective mono-N-methylation of aniline with dimethyl carbonate is carried out over faujasite Y zeolites. This one pot protocol is highly selective, favouring mono-N-methylation. Benzylation with dibenzyl carbonate is also found to be very selective, resulting in exclusive monobenzylation. Other advantages such as lower temperature, less rigorous reaction conditions, absence of C-alkylation products, etc., are also highlighted.

DOI : 10.1016/j.molcata.2004.03.047

Anahtar Kelimeler : Aniline, Mono-N-methylation/benzylation, Faujasite zeolites

Cilt: 218
Sayı: 2
Sayfa: 196-201
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organometalik Kimya %35

Kataliz %26

7

Methyltrioxorhenium on silica–alumina as metathesis catalyst of 1-octene

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

T.M Mathew , J.A.K du Plessis , J.J Prinsloo

Yıl :

1999

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Methyltrioxorhenium (MTO) supported on silica–alumina acts as a heterogeneous catalyst for the metathesis of 1-octene. 7.5% (m/m) MTO on the support gave a maximum percentage of homo-metathesis products. The reaction reached equilibrium after 1.5 h at room temperature. Addition of cesium ions onto the silica–alumina support increased the selectivity towards homo-metathesis products but decreased the total metathesis activity. The optimum percentage of cesium ions on the support was found to be 3.3%. Addition of 1% oxygen-containing additives to the 1-octene like 2-hexanone, pentanal, butanol and pentanoic acid, increased the homo-metathesis products and decreased the cross-metathesis products of 1-octene catalysed by the MTO/SiO2·Al2O3 catalytic system. Higher concentrations of additives decreased the activity of the catalytic system.

DOI : 10.1016/S1381-1169(99)00037-0

Anahtar Kelimeler : Methyltrioxorhenium, Metathesis, 1-Alkenes, Catalysis

Cilt: 148
Sayı: 1-2
Sayfa: 157-164
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Kataliz %97

8

Rhodium(I) mediated arylation of aldehydes with arylboronic acids under base and water free conditions: A computational study

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Alma Itzel Olivos Suarez , Joost N.H. Reek , Bas de Bruin

Yıl :

2010

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The mechanism for rhodium(I) mediated arylation of aromatic aldehydes by arylboronic acids under base and water free conditions was investigated with DFT methods. The detailed picture resulting from the calculations is that the reaction proceeds via an internal base mechanism, whereby the initially formed alcoholate (obtained by aryl migration to the aldehyde) attacks the electrophilic boron atom of the coordinated arylboronic acid substrate to facilitate the aryl transfer to the metal. Alternative pathways involving B–C oxidative addition or internal proton transfer followed by β-aryl transfer from thus resulting Rh–O–BPh(OH) moieties are kinetically disfavored. The rhodium atom does not change its oxidation state throughout this whole process, and all steps proceed smoothly within the coordination sphere of rhodium(I). Aldehyde migratory insertion into the RhI-aryl bond appears to be the rate limiting step (ΔG† = +19.4 kcal mol−1) of the catalytic cycle. The subsequent elementary steps involved in the transmetallation process proceed with lower barriers (<+16.3 kcal mol−1). The cis-[Rh(OH-CHPh2)(OBOHPh)(PNH2(OH)2)2] species R.S. should be the resting state species under the catalytic conditions according to the DFT calculations.

DOI : 10.1016/j.molcata.2010.03.002

Anahtar Kelimeler : Arylboronic acid, Rhodium, Aldehyde, Arylation, DFT

Cilt: 324
Sayı: 1-2
Sayfa: 24-30
ISSN: 1381-1169

9

Homogeneous and heterogeneous catalyzed three-step synthesis of 2-ethylheptanoic acid from carbon dioxide, butadiene and hydrogen

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Arno Behr , Volker A Brehme

Yıl :

2002

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

This paper describes the synthesis of 2-ethylheptanoic acid (2) by hydrogenation of the δ-lactone (1), which is on his part very well available by the reaction of butadiene with carbon dioxide. A two-step hydrogenation process was found to be the most successful reaction pathway. First of all the cleavage of the δ-lactone ring is applied. This process involves a homogeneously catalyzed two-phase hydrogenation with a water-soluble in situ rhodium-phosphine catalyst. The effects of ligand, temperature, hydrogen pressure and catalyst concentration have been examined. The catalyst containing aqueous phase has been recycled five times without loss of activity. The leaching of the rhodium into the organic phase was measured and found to be in the range of 1 wt.% of the starting catalyst concentration. The hydrogenation of the remaining double bonds was carried out with a heterogeneous palladium/charcoal catalyst in methanol.

DOI : 10.1016/S1381-1169(02)00190-5

Anahtar Kelimeler : Hydrogenation, Homogeneous catalysis, Biphasic catalysis, Carbon dioxide, Lactone

Cilt: 187
Sayı: 1
Sayfa: 69-80
ISSN: 1381-1169

10

Manganese porphyrin in solution and heterogenized in different materials mediates oxidation of hydrocarbons by iodosylbenzene

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Gabriel Kaetan Baio Ferreira , Kelly Aparecida Dias de Freitas Castro , Guilherme Sippel Machado , Ronny Rocha Ribeiro , Katia Jorge Ciuffi , Gustavo Pimenta Ricci , Jacqueline Aparecida Marques , Shirley Nakagaki

Yıl :

2013

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

We prepared a free base porphyrin (HP) containing hydroxy and methoxy groups in the mesophenyl substituents of the porphyrin ring. We then inserted Mn(III) ion into the resulting HP, to obtain MnP. We used silica synthesized by the sol–gel process to immobilize the MnP in either acidic or basic medium, which afforded the solids MnPA and MnPB, respectively. We also conducted the solvothermal Mn(III) ion insertion into HP, which furnished the self-structured solid MnPS. Because the MnP was catalytically active in homogeneous medium, we investigated the activity of all the prepared solids as heterogeneous catalysts in the oxidation of various hydrocarbons. MnPA, MnPB, and MnPS presented similar or higher activity than the homogeneous MnP in the oxidation of cyclooctene, cyclohexene, cyclohexane and n-heptane. Concerning alkane oxidation, the heterogeneous catalysts were more selective for the alcohol than the MnP in homogeneous solution. Moreover, the solid catalysts favored the oxidation of linear alkane, with selectivity toward the primary alcohol. We were able to recover all the solids at the end of the reaction and reuse them.

DOI : 10.1016/j.molcata.2013.06.022

Anahtar Kelimeler : Porphyrin, Heterogeneous catalysis, Oxidation, Silica, Self-assembly

Cilt: 378
Sayı: 0
Sayfa: 263-272
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Kataliz %62

Organometalik Kimya %33

11

Syntheses, structure, redox and catalytic epoxidation properties of dioxomolybdenum(VI) complexes with Schiff base ligands derived from tris(hydroxymethyl)amino methane

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Yan Sui , Xirui Zeng , Xiaoniu Fang , Xiangkai Fu , Yiu2019an Xiao , Li Chen , Menghua Li , Shu Cheng

Yıl :

2007

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Five kinds of dioxomolybdenum(VI) complexes with Schiff base ligands derived from tris(hydroxymethyl)amino methane are prepared and structurally characterized by X-ray crystallography, which reveals that these complexes adopt a distorted octahedral six-coordinate configuration formed by the tridentate Schiff base ligand, one coordinating water and two binding oxygen atoms. These complexes show good catalytic activities and selectivity in the epoxidation of cyclohexene with t-butylhydroperoxide, especially for complex 4, which could give a nearly 100% of epoxidation conversion and selectivity. Introduction of the electron-withdrawing group to the salicylidene ring of complex strongly increases the effectiveness of a catalyst, but decreases the redox stability of a complex.

DOI : 10.1016/j.molcata.2007.01.032

Anahtar Kelimeler : Epoxidation, Homogeneous catalysis, Dioxomolybdenum(VI) complexes, Tris(hydroxymethyl)amino methane, Schiff base ligands

Cilt: 270
Sayı: 1-2
Sayfa: 61-67
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organometalik Kimya %100

12

Mn(III)-tetraarylporphyrins bearing covalently bonded crown-ethers: synthesis and catalytic activity in 1-dodecene epoxidation promoted by aqueous HOClOCl−

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Stefano Banfi , Amedea Manfredi , Fernando Montanari , Gianluca Pozzi , Silvio Quici , Felice Ursino

Yıl :

1996

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Mn(III)-complexes of tetraarylporphyrins 1–4 bearing a crown-ether covalently linked through a single flexible chain have been synthesized. Their basic frame is that of the robust tetra-(2,6-dichlorophenyl)porphyrin 5 and the chain is connected by ether linkage either to the ortho (1–2) or to the meta positions (3–4) of one meso-aryl group. Catalytic efficiency was tested in the epoxidation of the poorly reactive 1-dodecene at 0°C under CH2Cl2H2O two-phase conditions in the presence of NaOCl (pH 9.5–10.0) as oxygen donor. The results obtained led us to propose a general acid/base catalysis as an explanation for the positive effect of crown-ethers in the alkene epoxidations with this catalytic system.

DOI : 10.1016/S1381-1169(96)00154-9

Anahtar Kelimeler : Functionalized Mn(III)-porphyrins, Crown ethers, 1-Dodecene epoxidation, NaOCl promoted epoxidation

Cilt: 113
Sayı: 1-2
Sayfa: 369-377
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organometalik Kimya %99

13

Functionalization of the naturally occurring linalool and nerol by the palladium catalyzed oxidation of their trisubstituted olefinic bonds

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Luciana A. Parreira , Ana F. Azevedo , Luciano Menini , Elena V. Gusevskaya

Yıl :

2017

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Linalool and nerol, bio-renewable terpenic alkenyl alcohols found in many essential oils, were selectively oxidized by molecular oxygen in the presence of the chloride-free Pd(OAc)2/p-benzoquinone catalytic system. An efficient dioxygen-coupled catalytic turnover was achieved in the absence of auxiliary electron-transfer mediators under 5–10 atm of oxygen pressure. In both substrates, only one of two olefinic bonds was involved in the interaction with palladium, whereas the other one remained intact. Primary allylic acetates were formed as major reaction products: 8-linalyl acetate and 8-neryl acetate from linalool and nerol, respectively. In the case of linalool, the intramolecular cyclization product (known as herboxide), also resulted from the oxidation of the internal double bond, was also formed in significant amounts. All monoterpenic compounds obtained in the present work are natural products found in exotic plants or grape wines and are potentially useful as fragrance ingredients due to their pleasant scents.

DOI : 10.1016/j.molcata.2016.07.033

Anahtar Kelimeler : Bio-renewables, Linalool, Nerol, Oxidation, Oxygen, Palladium

Cilt: 426
Sayı: 0
Sayfa: 429-434
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organik Kimya %52

Organometalik Kimya %38

14

Maximization of regioselectivity in hydroformylation of vinyl-aromatics using simple factorial design

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Andreia F. Peixoto , Mariette M. Pereira , Alberto A.C.C. Pais

Yıl :

2007

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The importance of hydroformylation reactions for fundamental organic and industrial synthesis has prompted a detailed analysis of the factors governing the regioselectivity of these processes. A simple 2k factorial design has shown that a very significant increase in the regioselectivity of vinyl-aromatics (typically from 70% to more than 98%) can be obtained by the exclusive manipulation of two variables, pressure and temperature, within the usual working values for such variables. It is also shown that optimised values can be obtained from within a range of possible values. The role of the ligand in the overall response of the system is also discussed and analysed.

DOI : 10.1016/j.molcata.2006.11.040

Anahtar Kelimeler : Factorial design, Hydroformylation, Regioselectivity

Cilt: 267
Sayı: 1-2
Sayfa: 234-240
ISSN: 1381-1169

Sınıflandırma :

Kimya %99

Organometalik Kimya %74

15

Competitive catalytic epoxidation and oxidative cleavage of stilbene by ruthenium complexes

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Antonino Morvillo , Mario Bressan

Yıl :

1997

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The catalytic oxidation of stilbenes, cis- and trans-, by iodosobenzene in the presence of the diphosphino-complexes of ruthenium(II) [RuCI(LL)2]PF6 (LL = 1,3-bis(diphenylphosphino) propane, DPP; 1-diphenylphosphino-2-(2′pyridyl)ethane, PPY) gives rise to stilbene epoxides, cis- and trans-, and to benzaldehyde with distinctly different kinetic pathways. The reaction is first-order to the catalyst fpr the epoxidation and second-order for the oxidative cleavage, whereas the rate dependence upon substrate concentration indicates reversible formation of a common catalyst-substrate intermediate.

DOI : 10.1016/S1381-1169(97)00086-1

Anahtar Kelimeler : Epoxidation, Oxidative cleavage, Stilbene, Ruthenium

Cilt: 125
Sayı: 2-3
Sayfa: 119-125
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

16

Application of heterogeneous solid acid catalysts for Friedlander synthesis of quinolines

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Biswanath Das , Kongara Damodar , Nikhil Chowdhury , Rathod Aravind Kumar

Yıl :

2007

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The catalytic activity of various heterogeneous solid acid catalysts including NaHSO4-SiO2, H2SO4-SiO2, Amberlyst-15 and HClO4-SiO2 on the Friedlander synthesis of quinolines has been studied. Amberlyst-15 has been found to be most effective in terms of the reaction times, yields and reusability of the catalyst. A series of quinolines have been prepared using this catalyst.

DOI : 10.1016/j.molcata.2007.04.034

Anahtar Kelimeler : Friedlander synthesis, Quinoline, Heterogeneous solid acid catalyst, Amberlyst-15

Cilt: 274
Sayı: 1-2
Sayfa: 148-152
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organik Kimya %56

Kataliz %41

17

Deactivation causes of supported palladium catalysts for the oxidative carbonylation of phenol

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Chaofan Yin , Jie Zhou , Qiming Chen , Jinyu Han , Yuanxin Wu , Xiaojun Yang

Yıl :

2016

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Palladium catalysts supported on manganese oxides octahedral molecular sieves (OMS-2), Pb doped OMS-2 (Pb-OMS-2) and perovskite-type La0.5Pb0.5MnO3 were prepared for investigating the deactivation causes of catalysts during the oxidative carbonylation of phenol. The catalytic experiments on three different sets of catalysts demonstrated that they were inactive after continuous reaction for 22 h. XRD patterns and HRTEM images demonstrated that carbonaceous pollution and palladium leaching occurred during the reaction process. The solvent and oxygen have significant impact on the palladium leaching by ICP-AES analysis. In addition, hot filtration tests and SH-HZSM-5 adsorption studies indicated that the leached palladium species are not active species. The results of XPS patterns and H2-TPR profiles showed that aggregation and reduction of Pd species was another deactivation cause. It was discovered that lattice oxygen species decreased and palladium aggregated, which hindered the re-oxidation of Pd(0) to Pd(II). In summary, carbonaceous pollution, Pd leaching, aggregation and consumption of oxygen species hindered the redox recycling of palladium, which resulted in the deactivation of supported palladium catalysts for the oxidative carbonylation of phenol.

DOI : 10.1016/j.molcata.2016.07.028

Anahtar Kelimeler : Diphenyl carbonate, Oxidative carbonylation, Deactivation causes, Pd leaching, Oxygen species

Cilt: 424
Sayı: 0
Sayfa: 377-383
ISSN: 1381-1169

18

Oxidation of phenol, styrene and methyl phenyl sulfide with H2O2 catalysed by dioxovanadium(V) and copper(II) complexes of 2-aminomethylbenzimidazole-based ligand encapsulated in zeolite-Y

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Mannar R. Maurya , Anil K. Chandrakar , Shri Chand

Yıl :

2007

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Interaction of oxovanadium(IV) exchanged zeolite-Y with the Schiff base derived from salicylaldehyde and 2-aminomethylbenzimidazole (Hsal-ambmz) in refluxing methanol followed by aerial oxidation leads to the formation of encapsulated dioxovanadium(V) complex, [VO2(sal-ambmz)]-Y(1). Similar reaction with copper(II) exchanged zeolite-Y followed by its treatment with aqueous NaCl gave encapsulated copper(II) complex, [Cu(sal-ambmz)Cl]-Y(2). These encapsulated complexes have been characterized by spectroscopic studies, thermal analysis and scanning electron micrographs (SEMs) as well as X-ray diffraction patterns. 3D model structure generated for neat complex [VO2(sal-ambmz)] suggests that zeolite-Y can accommodate these complexes in its nano-cavity without any strain. The encapsulated materials are active catalysts for the oxidation of phenol, styrene and methyl phenyl sulfide using H2O2 as an oxidant. Under the optimised reaction conditions about 42% conversion of phenol was obtained with these catalysts where the selectivity of catechol varied in the order: 2 (73.9%) >1 (65.2%). With the conversion of 97.0% with 1 or 56.7% with 2, the oxidation of styrene gave styrene oxide, benzaldehyde, benzoic acid, 1-phenylethane-1,2-diol and phenylacetaldehyde as major products. A maximum of 96.1% (with 1) conversion of methyl phenyl sulfide was observed in which the selectivity of major product methyl phenyl sulfoxide was found to be ca. 98%.

DOI : 10.1016/j.molcata.2006.08.084

Anahtar Kelimeler : Zeolite-Y, Encapsulation, Catalyst, VO2(sal-ambmz)-Y, Cu(sal-ambmz)Cl-Y, Phenol oxidation, Oxidation of styrene, Oxidation of methyl phenyl sulfide

Cilt: 263
Sayı: 1-2
Sayfa: 227-237
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Kataliz %76

Organometalik Kimya %20

19

Immobilized chiral Mn(III) salen complexes on co-condensed imidazole-functionalized mesoporous materials: Effective catalysts for asymmetric epoxidation of olefins

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Lan-Lan Lou , Huanling Du , Kai Yu , Shu Jiang , Wenjun Yu , Shuangxi Liu

Yıl :

2013

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The heterogeneous chiral Mn(III) salen catalysts with ordered hexagonal mesostructure were prepared based on mesoporous materials functionalized by imidazole groups through a co-condensation procedure. These catalysts were highly active and enantioselective for the asymmetric epoxidation of olefins. Within a short reaction time, comparable conversion and enantiomeric excess to those of the homogeneous counterpart were obtained even with a very low catalyst dosage (0.60 mol%). Thus notably high turnover frequencies (up to 165 h−1) were provided by these catalysts, attributed in part to the homogeneous distribution of the active centers as well as the strong electron-donating ability of imidazole groups. Comparison experiments showed that these catalysts were twice more active than the catalysts supported on the mesoporous material graft-modified with imidazole. Furthermore, the nanopore size of mesoporous hybrid supports was found to have a considerable effect on the catalytic performance.

DOI : 10.1016/j.molcata.2013.04.028

Anahtar Kelimeler : Chiral Mn(III) salen complex, Co-condensation, Imidazole-modified mesoporous material, Asymmetric epoxidation, Pore size

Cilt: 377
Sayı: 0
Sayfa: 85-91
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Kataliz %94

20

Selective double bond isomerization of allyl phenyl ethers catalyzed by ruthenium metal complexes

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Sumeet K. Sharma , Vivek K. Srivastava , Raksh V. Jasra

Yıl :

2006

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The RuCl2(PPh3)3 and RuCl3(AsPh3)2·CH3OH complex catalysts were studied for the double bond isomerization of methyl chavicol and eugenol in the polar aprotic (DMSO, acetonitrile), polar protic (ethanol, methanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-hexanol) and non-polar (benzene, toluene, n-hexane, cyclohexane, tetrahydrofuran) solvents. The highest conversion of methyl chavicol (99.7%) with 95.4% selectivity of trans-anethole was observed in ethanol using RuCl2(PPh3)3 catalyst. However, 94.2% conversion of methyl chavicol with 98.6% selectivity of trans-isomer was observed using methanol as a solvent in RuCl3(AsPh3)2·CH3OH. The kinetics of isomerization of methyl chavicol and eugenol using RuCl2(PPh3)3 and RuCl3(AsPh3)2·CH3OH catalysts in ethanol or methanol involving the effect of substrate concentrations, catalyst amount, solvents and temperature on the initial rate of reaction was studied in details. The initial rates of reaction were observed to increase on increasing the initial concentrations of methyl chavicol, eugenol and catalysts. However, the initial rate of reaction decreased on increasing the solvent concentration. Activation energies for the isomerization of methyl chavicol were calculated using RuCl2(PPh3)3 and RuCl3(AsPh3)2·CH3OH catalysts and were found to be 4.3 and 6.0 kJ/mol, respectively. Activation energy for the isomerization of eugenol was found to be 6.9 kJ/mol using RuCl2(PPh3)3 complex catalyst. The RuCl2(PPh3)3 complex was recycled five times for the isomerization of methyl chavicol and eugenol.

DOI : 10.1016/j.molcata.2005.10.005

Anahtar Kelimeler : Methyl chavicol, trans-Anethole, Eugenol, Isomerization, Kinetics, Ruthenium

Cilt: 245
Sayı: 1-2
Sayfa: 200-209
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Kimya ve Gıda Bilimi %72

21

Catalytic oxidation of organosulfides to sulfoxides using two novel Cu(II) and Ni(II) complexes with aqueous H2O2: Effect of TMAO promoter on oxidation of organosulfides

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Ali Nemati Kharat , Abolghasem Bakhoda , Taraneh Hajiashrafi

Yıl :

2010

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Two new copper(II) and nickel(II) complexes [Cu(MeOH)(O–NO2)(L)](NO3)·CH3OH (1) and [Ni(L)2(NO3)2]·H2O (2) derived from the 4′-(2-thienyl)-2,2′,6′,2″-terpyridine (L) were synthesized. The ligand and complexes were characterized with elemental analysis, 1H and 13C NMR, IR spectroscopy and finally the solid structure of complexes were determined by X-ray crystallography. Complexes (1) and (2) were tested as homogenous catalysts for sulfoxidation of a variety of organosulfide substrates utilizing hydrogen peroxide in the presence of a catalytic amount of trimethylamine N-oxide (TMAO). Addition of TMAO to the reaction mixture enhanced the conversion and selectivity.

DOI : 10.1016/j.molcata.2010.10.002

Anahtar Kelimeler : 4u2032-(2-Thienyl)-2, 2u2032, 6u2032, 2u2033-terpyridine, Sulfoxidation, Trimethylamine N-oxide, X-ray crystallography

Cilt: 333
Sayı: 1-2
Sayfa: 94-99
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organometalik Kimya %91

22

The regioselective biphasic hydrogenation of trans-cinnaldehyde by meta sulfonatophenyl-diphenylphosphine (TPPMS) Ru(II) and Os(II) species. The influence of ionic strength, ligand tensoactivity and metal nature in the selective production of the unsaturated alcohol

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

F. López-Linares , M.G. Gonzalez , D.E. Páez

Yıl :

1999

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The hydrogenation of trans-cinnamaldehyde was studied, using as catalyst precursor the complexes MCl2(CH3CN)4, where M=Ru(II) and Os(II), stabilized with the water-soluble ligand, meta-sulfonatophenyl-diphenylphosphine, in its sodium salt form, (TPPMS). The Ru(II) system showed better activity and selectivity than its Os(II) analogue, under biphasic catalysis. For the ruthenium system an enhancement of the selectivity to the unsaturated alcohol was obtained by increasing substrate to catalyst ratio, salt concentration and ligand tensoactivity.

DOI : 10.1016/S1381-1169(99)00097-7

Anahtar Kelimeler : Regioselective biphasic hydrogenation, Trans-cinnaldehyde, Unsaturated alcohol

Cilt: 145
Sayı: 1-2
Sayfa: 61-68
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organometalik Kimya %100

23

Magnetic core–shell carbon microspheres (CMSs)@ZnFe2O4/Ag3PO4 composite with enhanced photocatalytic activity and stability under visible light irradiation

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Xiaojuan Chen , Youzhi Dai , Tanhua Liu , Jing Guo , Xingyan Wang , Fenfang Li

Yıl :

2015

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Novel magnetic core–shell visible light responsive carbon microspheres (CMSs)@ZnFe2O4/Ag3PO4 composite photocatalyst with different mass ratios have been successfully synthesized through the solvothermal and in situ precipitation methods for the first time. The characteristics of the as-prepared materials were systematically determined by the XRD, XPS, SEM, FESEM-EDS, UV–vis DRS, VSM, and PL etc.; the results indicated that all of the composites showed good crystallinity and strong absorbance both in the UV and visible light regions. Moreover, a heterojunction structure was formed between the ZnFe2O4 and Ag3PO4. The photocatalytic performance of the composite was evaluated for 2,4-dichlorophenol (2,4-DCP) degradation, and enhanced photocatalytic activity and stability were achieved. When the mass ratio of CMSs, ZnFe2O4, and Ag3PO4 in the composite was 2:1:3, the apparent photodegradation rate constant of 2,4-DCP was 0.0184 min−1, which was 7.36 times that of ZnFe2O4, 2.45 times that of Ag3PO4, and 4 times that of [email protected]2O4 (mass ratio = 2:1). And after four times recycling, the photodegradation efficiency of 2,4-DCP over the [email protected]2O4/Ag3PO4 (mass ratio = 2:1:3) can even reach approximately 89%. The investigation of the photocatalytic mechanism suggested that both the effective separation of the photoinduced electron–hole pairs and the active free radicals formed in the special core-shell interface contributed to the superior photocatalytic performance of the composite.

DOI : 10.1016/j.molcata.2015.08.021

Anahtar Kelimeler : Ag3PO4, ZnFe2O4, Carbon microspheres, Coreu2013shell structure, Visible light photocatalysis

Cilt: 409
Sayı: 0
Sayfa: 198-206
ISSN: 1381-1169

Sınıflandırma :

Malzeme Bilimi %51

İnorganik kimya %94

Kimya %49

Kataliz %99

24

Selectively catalytic epoxidation of α-pinene with dry air over the composite catalysts of Co–MOR(L) with Schiff-base ligands

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

X.-H. Lu , J. Lei , X.-L. Wei , X.-T. Ma , T.-J. Zhang , W. Hu , D. Zhou , Q.-H. Xia

Yıl :

2015

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Twelve bi-/tridentate Schiff-base ligands (L1–L12) have been designed, synthesized and coordinated with ion-exchanged Co–MOR (Mordenite) forming a series of Co–MOR(L) composite catalysts, for which various analyzes and characterizations are conducted. Selectively catalytic epoxidation of α-pinene with dry air over Co–MOR(L) catalysts has been carried out, where uses TBHP in small amounts as the initiator. Among these Co–MOR(L) catalysts, Co–MOR(L8) exhibits the best activity for the titled reaction to obtain 85.8 mol% conversion and 90.8% selectivity of epoxide. Some factors such as the structure of ligands, the oxidants, the solvents, the catalyst amount, the reaction temperature and time play important roles in controlling the epoxidation. The recyclable stability of the Co–MOR(L8) catalyst is confirmed. The studies on the electrochemical behaviors of Co species in Co–MOR(L8) reveal the importance of reversible change between Co oxidation states for the epoxidation.

DOI : 10.1016/j.molcata.2015.02.006

Anahtar Kelimeler : Cou2013MOR(L), Schiff-base ligands, Epoxidation, α-Pinene, Air

Cilt: 400
Sayı: 0
Sayfa: 71-80
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Kataliz %96

25

Olefin metathesis and isomerization: From undesired side reactions to useful synthetic methodology

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Bernd Schmidt

Yıl :

2006

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Conversion of ruthenium carbene complexes to ruthenium hydride complexes by organometallic transformations in situ opens up interesting synthetic perspectives. In this account the use of Grubbs’ catalyst to synthesize pent-4-enals selectively from diallyl- and allyl homoallyl ethers and scope and limitations of a Tandem RCM-isomerization sequence for the synthesis of cyclic enol ethers are discussed.

DOI : 10.1016/j.molcata.2006.03.026

Anahtar Kelimeler : Metathesis, Ruthenium, Isomerization, Tandem reaction

Cilt: 254
Sayı: 1-2
Sayfa: 53-57
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organometalik Kimya %100

26

Nickel-catalyzed direct C–H arylation of unactivated arenes with aryl halides

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Guanlei Xie , Tingyi Li , Xiaoming Qu , Jincheng Mao

Yıl :

2011

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Ni(OAc)2·4H2O could catalyze direct C–H arylation of unactivated arenes with aryl halides in presence of 1,10-phenanthroline without using additives.

DOI : 10.1016/j.molcata.2011.03.007

Anahtar Kelimeler : Ni complexes, Cu2013H arylation, Aryl halides, Unactivated arenes, Additives

Cilt: 340
Sayı: 1-2
Sayfa: 48-52
ISSN: 1381-1169

Sınıflandırma :

Kimya %100

Organometalik Kimya %100

27

Activities of supported copper oxide catalysts in the NO+CO reaction at low temperatures

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Yuhai Hu , Lin Dong , Jun Wang , Weiping Ding , Yi Chen

Yıl :

2000

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

The activities of copper oxide supported on CeO2, γ-Al2O3 and ceria-modified γ-Al2O3 catalysts for the NO+CO reaction at low temperature (200°C) have been investigated. The results show that the activities of the surface-dispersed copper species are greatly enhanced due to the presence of ceria, whether it was used as a support or as the pre-dispersed species on γ-Al2O3. The activities decrease in the order: CuO/CeO2>CuO/CeO2/γ-Al2O3>CuO/γ-Al2O3. For the CuO/CeO2/γ-Al2O3 catalysts, it is shown that NO conversions are not improved significantly with the increasing of CuO and/or ceria loadings, however, the turn-over number for the catalysts is found to be strongly relative to ceria loadings. By a combination of X-ray diffraction (XRD), electron spin resonance (ESR) and temperature programmed reduction (TPR) results, the states and properties of copper oxide species, as well as the interactions among the surface-dispersed copper oxide species, ceria species and support, are also studied. All the results are tentatively discussed according to the incorporation model proposed previously.

DOI : 10.1016/S1381-1169(00)00299-5

Anahtar Kelimeler : NO reduction, Supported catalysts, Ceria, CuO, ESR, XRD, TPR

Cilt: 162
Sayı: 1-2
Sayfa: 307-316
ISSN: 1381-1169

Sınıflandırma :

Kimya %90

Kataliz %100

28

Supported metal cluster catalysts

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

B.C Gates

Yıl :

2000

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Highly dispersed metal catalysts containing supported clusters of only several metal atoms each, exemplified by Ir4 and Ir6, were prepared by removal of CO ligands from supported precursors, for example, [Ir4(CO)12] and [Ir6(CO)16]. Transmission electron microscopy (TEM), extended X-ray absorption fine structure spectroscopy and density functional theory indicate the metal–support-oxygen coordination numbers and distances, which identify the supports as multidentate oxygen-donor ligands. Theory indicates that Ir4 clusters in zeolite NaX are neutral or slightly negatively charged and that cluster-support bonding induces a polarization of the cluster that could affect reactivity and catalysis. Supported catalysts prepared from precursors with noble metal-oxophilic metal bonds are modeled as clusters of a few atoms of the noble metal ‘nested’ in a supported cluster of the oxophilic metal oxide, which helps to anchor and stabilize the noble metal clusters. Changes in the oxide support have only modest effects on the catalytic activities of supported metal clusters for toluene hydrogenation, but the catalytic activity of γ-Al2O3-supported Ir clusters per exposed Ir atom increases with increasing cluster size, and this observation remains to be explained.

DOI : 10.1016/S1381-1169(00)00399-X

Anahtar Kelimeler : Catalysts, Metal clusters, Transmission electron microscopy

Cilt: 163
Sayı: 1-2
Sayfa: 55-65
ISSN: 1381-1169

Sınıflandırma :

Kimya %99

Organometalik Kimya %59

Kataliz %39

29

Photocatalytic hydrogen generation in the presence of ethanolamines over Pt/ZnIn2S4 under visible light irradiation

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Yuexiang Li , Kai Zhang , Shaoqin Peng , Gongxun Lu , Shuben Li

Yıl :

2012

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

Using ethanolamine (EA), diethanolamine (di-EA) and triethanolamine (tri-EA) as electron donors, the photocatalytic hydrogen evolution and decomposition of the electron donors (pollutants) over Pt/ZnIn2S4 have been investigated. The Pt was deposited on ZnIn2S4 by in situ photoreduction. The three ethanolamines improve notably photocatalytic hydrogen generation with their simultaneous degradation, and their activity order for hydrogen evolution is tri-EA ≫ di-EA > EA. The adsorption of these donors on ZnIn2S4 was monitored by in situ attenuated total reflection infrared spectroscopy (ATRIR). The order of their adsorption intensity is EA > di-EA ≫ tri-EA. The activity order depends on their molecular structure and adsorption performance. The effect of concentration of the pollutants on the hydrogen generation rate is consistent with a Langmuir–Hinshelwood kinetic model. The weak basic condition is favorable for the photocatalytic hydrogen generation. A possible reaction mechanism was discussed.

DOI : 10.1016/j.molcata.2012.07.011

Anahtar Kelimeler : Photocatalysis, Hydrogen evolution, Ethanolamine, Adsorption, ZnIn2S4

Cilt: 363-364
Sayı: 0
Sayfa: 354-361
ISSN: 1381-1169

Sınıflandırma :

Kimya %99

Kataliz %100

30

Ethylbenzene dehydrogenation in the presence of carbon dioxide over magnesia-supported iron oxides

Araştırma Makalesi

Kaynak :

Science Direct

Yayıncı :

Journal of Molecular Catalysis A: Chemical

Yazar(lar) :

Maria do Carmo Rangel , Ana Paula de Melo Monteiro , Sergio Gustavo Marchetti , Sirlene Barbosa Lima , Márcia de Souza Ramos

Yıl :

2014

Journal of Molecular Catalysis A: Chemical

Yayıncı Web Sitesi Tam Metin Özet Ek Bilgiler

Kaydet

In recent years, several works have been addressed to decrease carbon dioxide emission or to capture, to storage and to use it. An attractive option is its use as feedstock of chemical industry, especially in dehydrogenation reactions (such as ethylbenzene dehydrogenation to produce styrene), providing an exothermic process which can be operated at lower temperatures, making negligible the cracking products. Aiming to find alternative catalysts for this reaction, magnesia-supported iron oxides were studied, being prepared by two different methods. The classical impregnation produced a spinel (MgFe2O4) co-existing with magnesia containing Fe3+ species, this catalyst showing higher specific surface area and being more active and selective than magnesia. Moreover, the deposition of iron nanoparticles through a magnetic fluid on magnesia produced magnesia-supported hematite nanoparticles co-existing with magnesia containing Fe3+ species. In this case, the specific surface area and the activity were even higher and the solid is much more reducible than the other sample. These findings were associated to hematite nanoparticles and to the lower tendency of iron species to diffuse into magnesia lattice. They show that the Fe3+ species are more active and selective to styrene as hematite nanoparticles than when they are in the environment of magnesium ferrite.

DOI : 10.1016/j.molcata.2014.03.002

Anahtar Kelimeler : Ethylbenzene, Styrene, Magnesium oxide, Iron oxide nanoparticles, Carbon dioxide

Cilt: 387
Sayı: 0
Sayfa: 147-155
ISSN: 1381-1169

Sınıflandırma :

Kimya %62

Kataliz %97

Malzeme Bilimi %38

Doğal Materyaller %37

Malzeme Mühendisliği %24