Enhancement of catalytic activity of titanosilicalite-1 - sulfated zirconia combination towards epoxidation of 1-octene with aqueous hydrogen peroxide

Prasetyoko, Didik; Ramli, Zainab; Endud, Salasiah; Nur, Hadi

doi:10.1007/s11144-005-0298-y

Cited by 9 publications

(12 citation statements)

References 6 publications

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“…Meanwhile, the higher activity observed in the sample with lower V 2 O 5 loading indicated that only small amount of V 2 O 5 is needed to increase the hydrophilicity of TS-1 to form peroxotitanium species. Similar findings have been reported by Prasetyoko et al [11], which reported that the yield of 1,2-epoxyoctane from 1-octene epoxidation decreased as WO 3 loading in TS-1 increased higher that 7 wt% due to the blocking pores of TS-1 by tungsten oxide WO 3 at the high amount of WO 3 loading in TS-1.…”

Section: B Catalytic Activitysupporting

confidence: 90%

“…Hydrophilic improvement of catalyst can be carried out by addition of metal oxide which leads to increasing of acidity properties. The metal oxide in TS-1 catalyst which act as acid site capable to increase catalyst hydrophilicity, so that reactant adsorption in catalyst becomes faster [10,11]. In previous research done by Indrayani [12], MoO 3 /TS-1 catalysts have showed improvement of hydrophilicity along with the increasing of MoO 3 content in MoO 3 /TS-1 catalyst.…”

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confidence: 99%

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Vanadium Contribution to the Surface Modification of Titanium Silicalite for Conversion of Benzene to Phenol

Mulyatun¹,

Prasetyoko²

2011

JTS

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AbstractVanadium oxide supported on the surface of titanium silicalite was investigated in benzene hydroxylation to determine its activity as heterogeneous catalyst. Effect of vanadium loading on structure and activity of titanium silicalite was investigated. On the basis of X-ray diffraction and infrared spectroscopy techniques, it was found that the titanium structure was remained on the modified catalyst. The catalytic activity of the modified catalyst was observed to be higher than that of parent catalyst.Keywordstitanium silicalite, vanadium oxide, hydroxylation, benzene AbstrakAktivitas vanadium oksida yang berada pada permukaan titanium silikalit sebagai katalis heterogen telah diteliti pada hidroksilasi benzena. Pengaruh loading vanadium terhadap struktur dan aktivitas titanium silikalit telah dipelajari. Berdasarkan teknik difraksi sinar-X dan spektroskopi inframerah, ditemukan bahwa titanium pada katalis yang telah dimodifikasi tidak mengalami perubahan struktur. Aktivitas katalitik dari katalis yang telah dimodifikasi diamati lebih tinggi dibandingkan dengan katalis induk.Kata Kuncititanium silikalit, vanadium oksida, hidroksilasi, benzenahenol is an important intermediate compound for the synthesis of petrochemicals, agrochemicals, and plastics. Nowadays approximately 95 % of phenol production was produced by cumene process consisting of three main reaction steps (alkylation of benzene with propylene to cumene, oxidation of cumene to cumene hydroperoxide and decomposition to phenol and acetone) [1]. The advantage of the cumene process is that it takes two inexpensive starting materials, benzene and propylene and converts them into two high value useful products, phenol and acetone, using air. Despite its great success, the cumene process has some disadvantages such as the production of an explosive intermediate (cumene hydroperoxide), it has a high environmental impact, and it uses a corrosive catalyst. It is multi-step process, which makes it difficult to achieve high phenol yields in relation to benzene used and which leads to a high capital investment. It requires the uses of aggressive media (dilute sulphuric acid at 60-70 o C) and has a high acetone production as a co-product which results in an over supply in the market [2]. This situation encouraged scientists to develop other methods for producing phenol from benzene, preferably via a single-step and free of coproducts reaction, which thus would be economically favorable.The direct hydroxylation of benzene to phenol is an attractive alternative to phenol production for economically and environmentally reason [3]. One of the alternative routes to produce phenol which has more Mulyatun is with Department of Chemical Education, Faculty of Education, Institut Agama Islam Negeri Walisongo, Semarang, Indonesia.Didik Prasetyoko is with Department of Chemistry, FMIPA, Institut Teknologi Sepuluh Nopember, Surabaya, 60111, Indonesia. E-mail: didikp@chem.its.ac.id. advantages is through benzene hydroxylation reaction using H 2 O 2 as oxidant agent a...

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Section: B Catalytic Activitysupporting

confidence: 90%

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confidence: 99%

Vanadium Contribution to the Surface Modification of Titanium Silicalite for Conversion of Benzene to Phenol

Mulyatun¹,

Prasetyoko²

2011

JTS

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“…Isolated metal centers and small oligomers of early transition metal oxides (e.g., Al III [14,15], Ti IV [7,[16][17][18], Zr IV [19,20], Ta V [21][22][23], and Nb V [24,25]) catalyze the epoxidation of olefins with H 2 O 2 . Isolated Nb atoms grafted onto silica give greater rates and selectivities for olefin epoxidation compared to isolated Ti centers as well those of other group IV and V metals (i.e., Zr, Hf, V, and Ta) on silica, which was attributed to differences between the Lewis acidity (estimated from the ionic character of the M-O bond) of the different metal atoms [20].…”

Section: Introductionmentioning

confidence: 99%

Kinetic and spectroscopic evidence for reaction pathways and intermediates for olefin epoxidation on Nb in *BEA

Bregante

Priyadarshini

Flaherty

2017

Journal of Catalysis

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2Graphical Abstract -TOC 3 AbstractThe selective epoxidation of olefins with hydrogen peroxide (H 2 O 2 ) over transition metal substituted zeolites is less environmentally impactful than epoxidation schemes that use chlorinated or organic oxidants. The structure and reactivity of reactive intermediates derived from H 2 O 2 and the mechanism for olefin epoxidation on such materials are debated. Here, cyclohexene oxide formation and H 2 O 2 decomposition rates (measured as functions of reactant and product concentrations) and in situ infrared (IR) and UV-vis spectroscopy are used to probe the intervening elementary steps for cyclohexene (C 6 H 10 ) epoxidation and the identity of the reactive intermediates on a Nb-β catalyst. IR and UV-vis spectra acquired in situ show that the reactive intermediates are predominantly superoxide species (Nb IV -(O 2 ) -; observed also by X-ray photoelectron spectroscopy), which form by the irreversible activation of H 2 O 2 over Nb centers.Similar M-(O 2 )* (M= Ti or Ta) intermediates were previously assumed to form via reversible processes; however, in situ IR and UV-vis measurements directly show that Nb IV -(O 2 )forms irreversibly in both H 2 O and acetonitrile. Activation enthalpies (ΔH ‡ ) for C 6 H 10 epoxidation are 27 kJ mol -1 higher than for H 2 O 2 decomposition, while activation entropies (ΔS ‡ ) for epoxidation are 56 J mol -1 K -1 lower than for H 2 O 2 . These comparisons show that the selectivities for epoxidation, via primary reaction pathways, increase with increasing reaction temperatures.Collectively, these results provide a self-consistent mechanism for C 6 H 10 epoxidation that is also in agreement with previously published data. These findings will aid the rational design and study of alternative metal oxide catalysts for olefin oxidation reactions.

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“…Zr and Hf organometallic complexes have been used for alkene epoxidation using tert-butyl hydroperoxide as the oxidant. 52 Our work facilitates the catalytic transfer of both oxygen atoms from molecular O 2 to substrate molecules (e.g., alkene) to produce substrate oxide molecules (e.g., alkene oxide) without requiring a coreductant. 49 A Zr organometallic complex activated molecular oxygen that subsequently epoxidized an olen group in a non-catalytic reaction in which the formed epoxide remained covalently bound to the metal and a methyl group on one of the ligands was irreversibly reduced to a methoxy group.…”

Section: Introductionmentioning

confidence: 99%

Hafnium catalysts for direct alkene epoxidation using molecular oxygen as oxidant

Manz

2015

RSC Adv.

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New zirconium (Zr) based organometallic catalysts for direct olefin epoxidation using O 2 as oxidant without coreductant were introduced in a previous computational study (T. A. Manz and B. Yang, RSC Adv., 2014, 4, 27755-27774). In this paper, we use density functional theory (DFT) to study three Hf-based catalysts with the same bis(bidentate) ligands as the preceding Zr-based catalysts: (a) the diimine ligand N(Ar)-CH-CH-N(Ar) aka NCCN, (b) the imine-nitrone ligand N(Ar)-CH-CH-N(Ar)-O aka NCCNO, and (c) the dinitrone ligand O-N(Ar)-CH-CH-N(Ar)-O aka ONCCNO [Ar ¼ -C 6 H 3 -2,6-i Pr 2 ]. Complete reaction cycles and energetic spans (i.e., effective activation energies for the entire catalytic cycle) are computed for propene epoxidation. For Hf_NCCNO and Hf_ONCCNO, the reaction cycles are similar to the Zr-basedanalogs and the formation of h 3 -ozone intermediates is still crucial. Hf_ONCCNO has a large enthalpic energetic span (60.4 kcal mol À1 ) due to forming inert octahedral complexes as the catalyst resting state.Our calculations predict an energetic span $40 kcal mol À1 for Hf_NCCN, which indicates it will not be a good catalyst. Computed enthalpic energetic spans of $30 kcal mol À1 are achieved for the Hf_NCCNO and Zr_NCCNO catalysts; however, transfer of allylic hydrogen from the reaction product forms a low energy deactivation product. Therefore, the Hf_NCCNO and Zr_NCCNO catalysts are only suitable for direct epoxidation of alkenes that do not have any allylic hydrogen atoms. As an example of an alkene with no allylic hydrogens, we computed enthalpic energetic spans (kcal mol À1 ) for direct ethylene epoxidation of (a) 25.0 for Hf_NCCNO, (b) 30.2 for Zr_NCCNO, and (c) 52.7 for Zr_NCCN. † Electronic supplementary information (ESI) available: DFT-optimized geometries and energies; imaginary frequency for each transition state; singlet-triplet crossing curves for O 2 addition to Hf_ONCCNO and Hf_NCCN dioxo complexes; constrained optimization curves showing oxo h 3 -ozone and peroxo h 3 -ozone complexes do not exist for the Hf_NCCN system; chemical potential diagrams for Hf_ONCCNO and Hf_NCCN; assigned spin magnetic moments tables; master cycle and table of reaction energies and energetic spans for direct propene epoxidation catalyzed by Hf_ONCCNO; master cycles and tables of reaction energies and energetic spans for direct ethylene epoxidation catalyzed by Zr_NCCN, Hf_NCCNO, and Zr_NCCNO. See

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Enhancement of catalytic activity of titanosilicalite-1 - sulfated zirconia combination towards epoxidation of 1-octene with aqueous hydrogen peroxide

Abstract: Titanosilicalite-1 (TS-1) in combination with sulfated zirconia efficiently catalyzes the epoxidation of 1-octene with aqueous hydrogen peroxide. The presence of both octahedral zirconium and sulfate species in the catalysts enhances the epoxidation rates.

Cited by 9 publications

References 6 publications

Vanadium Contribution to the Surface Modification of Titanium Silicalite for Conversion of Benzene to Phenol

Vanadium Contribution to the Surface Modification of Titanium Silicalite for Conversion of Benzene to Phenol

Kinetic and spectroscopic evidence for reaction pathways and intermediates for olefin epoxidation on Nb in *BEA

Hafnium catalysts for direct alkene epoxidation using molecular oxygen as oxidant

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