Catalyst For Hydroxylation Of Benzene Research Articles

Amorphous Vanadium Oxide Supported on Activated Carbon Prepared by Dielectric Barrier Discharge as an Efficient and Stable Catalyst for Hydroxylation of Benzene to Phenol

Amorphous Vanadium Oxide Supported on Activated Carbon Prepared by Dielectric Barrier Discharge as an Efficient and Stable Catalyst for Hydroxylation of Benzene to Phenol

Reusable citric acid modified V/AC catalyst prepared by dielectric barrier discharge for hydroxylation of benzene to phenol

A reusable and efficient citric acid modified V/AC catalyst for benzene hydroxylation was prepared using an environmentally benign DBD method.

Rational Designed Polymer as a Metal-Free Catalyst for Hydroxylation of Benzene to Phenol with Dioxygen

Direct hydroxylation of benzene to phenol with dioxygen is a green route for synthesis of phenol. The higher bonding energies of C–H in benzene and O–O in dioxygen make metal-free catalysis a challenge. A novel metal-free catalyst of quinone-cylcohexanone-formaldehyde polymer was rationally designed and prepared. The polymer was characterized with FT-IR, XRD, Raman, SEM, 13C NMR and XPS. Abundant oxygen functional groups of cyclic ketonic, quinone carbonyl and hydroquinone were found on the surface of polymer. The catalytic performances for hydroxylation of benzene to phenol with dioxygen over the metal-free catalyst were investigated and a phenol yielding of 11.4% was achieved. Moreover, the reaction mechanism was proposed.

Quinone-amine polymers as metal-free and reductant-free catalysts for hydroxylation of benzene to phenol with molecular oxygen.

Quinone-amine polymers were employed as metal-free and reductant-free catalysts for the hydroxylation of benzene to phenol with molecular oxygen, yielding phenol as high as the transition metal catalyst.

Iron- and Copper-exchanged Beta Zeolite Catalysts for Hydroxylation of Benzene to Phenol with H2O2

A new zeolite-based catalyst for direct conversion of benzene to phenol (BTP reaction) is reported. Both Fe- and Cu-exchanged Beta catalysts, Fe-Cu/Beta, were prepared by the aqueous ion-exchange m...

Ni–Mg co-doped ZnO nanoparticles as a novel catalyst for hydroxylation of benzene to phenol

Mg and Ni were introduced as the novel co-doping materials for synthesizing Mg and Ni co-doping ZnO nanoparticles (NPs) through the simple wet chemical method. Photocatalyst properties of Mg and Ni co-doping ZnO NPs were studied by hydroxylation of benzene to phenol at room temperature. Furthermore, the doped Mg and Ni cause the hydroxylation capability of ZnO to be enhanced which can be attributed to the presence of Mg and Ni on the ZnO NPs which greatly increases absorption in under the ultraviolet (UV) light range enabled by the surface plasmon resonance effect from Mg and Ni. In addition, an attempt was made to investigate the effects of several parameters such as hydroxylation reaction time, solvent, and concentration of H2O2 and photocatalyst, and UV irradiation on the hydroxylation yield. Mg and Ni co-doping ZnO NPs showed significant hydroxylation after two recyclings, resulting in 85 and 77% in the first and second recycling processes, respectively.

H5PMo10V2O40 immobilized on functionalized chloromethylated polystyrene by electrostatic interactions: a highly efficient and recyclable heterogeneous catalyst for hydroxylation of benzene

PMoV2/DMA16-CMPS was used as a highly efficient and recyclable heterogeneous catalyst for hydroxylation of benzene.

A Schiff-base-type vanadyl complex grafted on mesoporous carbon nitride: a new efficient catalyst for hydroxylation of benzene to phenol

VO(acac)2 was grafted on mesoporous g-CN material as a Schiff-base-type complex, and showed high catalytic activity in direct hydroxylation of benzene to phenol.

Vanadia supported on mesoporous carbon nitride as a highly efficient catalyst for hydroxylation of benzene to phenol

Vanadia supported on mesoporous carbon nitride catalyzed the hydroxylation of benzene with a high conversion of 18%, along with a superior TOF of 1.59 h−1 to other vanadia- and g-C3N4-based catalysts.

Facile Synthesis of Copper-doped Mesoporous Silica Pillared Clay (Cu-MSPC) as a High-performance Catalyst for Hydroxylation of Benzene to Phenol

Abstract A series of copper-doped mesoporous silica pillared clay (Cu-MSPC) with high catalytic performance on the hydroxylation of benzene to phenol have been synthesized with a facile process. The high conversion (31.1%) and selectivity (96%) toward phenol are achieved with only 4.16% copper loading. The characterization results show that the copper of these materials is doped in the intergallery silica pillar, leading to the high catalytic performance at low copper loadings. Meanwhile, the formation of Cu-MSPC structure is proposed.

Iron(III) Supported g-Al2O3 Catalyst for Hydroxylation of Benzene

Iron(III) Supported g-Al2O3 Catalyst for Hydroxylation of Benzene

Organometallic-polyoxometalate hybrid based on V-Schiff base and phosphovanadomolybdate as a highly effective heterogenous catalyst for hydroxylation of benzene

A novel organometallic-polyoxometalate hybrid has been prepared by anion-exchange of V Schiff base functionalized ionic liquid with V-containing Keggin-type polyoxometalate. The hybrid solid with two types of catalytic active V components demonstrates remarkable capability for heterogeneous hydroxylation of benzene with excellent phenol yield 19.6% and 100% selectivity. After reaction, the catalyst can be simply recovered by filtration and reused at least 4times without the change of catalyst structure. The synergistic effect between metal Schiff base complex and polyoxometalate plays an important role in the promotion of catalytic activity.

Direct hydroxylation of benzene to phenol with hydrogen peroxide catalyzed by a quinine heteropolyacid hybrid

A new heterogeneous hybrid catalyst designed for direct hydroxylation of benzene to phenol was prepared through modification of Keggin-structured phosphovanadomolybdate with quinine. The structure of the catalyst was fully characterized by Fourier transform infrared and ultraviolet-visible spectroscopies, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, nitrogen sorption experiments, and CHN elemental analysis. The results indicated that the hybrid catalyst was a semi-amorphous heteropolyacid salt with high thermal stability, surface area, and pore volume. The catalytic activity of the hybrid for the hydroxylation of benzene with H 2 O 2 was assessed. The hybrid catalyst forms a liquid-solid biphasic system and exhibits high activity, convenient recovery, and reusability. The strong electronic interactions and hydrogen bonding networks formed between the π-electron-rich quinine framework and heteropolyanions are responsible for the solid nature and insolubility of the catalyst. The high surface area and improved redox properties of the Keggin heteropolyacid account for its excellent catalytic performance. The results of this work reveal a new, more facile way to prepare an efficient polyoxometalate-based catalyst for heterogeneous hydroxylation of benzene to phenol. A quinine-modified phosphovanadomolybdate hybrid is developed as a heterogeneous catalyst for hydroxylation of benzene. The redox properties of the heteropolyanion are improved by quinine, accounting for its excellent catalytic performance.

Carboxylic acid-functionalized phosphovanadomolybdate-paired ionic polymer as a green heterogeneous catalyst for hydroxylation of benzene

Abstract A novel PMoV-paired ionic polymer was prepared by anion-exchange of a newly task-specific designed carboxylic acid-functionalized ionic polymer with a Keggin V-containing heteropolyacid, and characterized by FT-IR, SEM, TG, XRD, 1H NMR, and CNH elemental analysis. Its catalytic performance for hydroxylation of benzene with H2O2 was studied using CH3CN as solvent. The obtained polymer is revealed to be a highly efficient heterogeneous catalyst for hydroxylation of benzene, showing a high yield to phenol 26.9% with 100% selectivity. The solid catalyst has a convenient recoverability with a considerable catalyst recovery rate of above 90%, and the reused catalyst in the fourth run showed a phenol yield of 17.8%.

Triethylamine-modified Keggin heteropolyacid: a novel phase-transfer catalyst for hydroxylation of benzene with H2O2

The Keggin-structured heteropolyacid H4PMo11VO40 and its triethylamine-modified derivative [(C2H5)3NH]4PMo11VO40 were prepared and characterized by FT-IR and UV–visible spectrometry, and elemental analysis. Direct hydroxylation of benzene to phenol by H2O2 over these two catalysts was then compared. The effect of the triethylamine in [(C2H5)3NH]4PMo11VO40 on the catalytic hydroxylation of benzene was investigated in detail. The results showed that although the triethylamine-modified catalyst is not significantly more active than the parent heteropolyacid catalyst, its reaction-controlled phase-transfer characteristics enable easy separation of the catalyst from the reaction medium, and its reuse, suggesting its potential for application to the hydroxylation of benzene to phenol with H2O2.

Heteropolyanion-paired cross-linked ionic copolymer: An efficient heterogeneous catalyst for hydroxylation of benzene with hydrogen peroxide

A heteropolyanion-based cross-linked ionic copolymer was prepared by the anion-exchange of heteropolyacid (HPA) H5PMo10V2O40 with polymeric ionic liquid (PIL) poly(divinylbenzene-3-n-butyl-1-vinylimidazolium)Br, and characterized by FI-IR, UV–vis, XRD, TG, SEM, elemental analysis and BET surface areas. The characterization results show that the ionic copolymer is an amorphous HPA salt of PIL-cation with a considerable thermal stability, high surface area and large pore volume. Further, the ionic copolymer is revealed to be a highly efficient heterogeneous catalyst for hydroxylation of benzene with H2O2 to phenol, showing high activity, convenient recovery and steady reuse. The excellent performance of the novel porous HPA-based copolymer catalyst is discussed in relation to its textural property and intramolecular charge transfer behavior.

Active phase of a Pd-Cu/ZSM-5 catalyst for benzene hydroxylation: In-situ XAFS studies

The gas-phase hydroxylation of benzene by using a mixture of oxygen and hydrogen has been carried out over Cu/ZSM-5 catalysts modified with palladium. In-situ X-ray absorption studies employed in the course of H2-tempereature programmed reduction (H2-TPR) followed by benzene hydroxylation confirmed that the oxidic phase of Cu2+ was transformed to Cu+ during the reaction. The addition of Pd to Cu/ZSM-5 noticeably improved the reducibility of the oxidic Cu phase, which resulted in an increase in the activity of the reaction.

Heteropolyanion-based ionic hybrid solid: A green bulk-type catalyst for hydroxylation of benzene with hydrogen peroxide

A novel heteropolyanion-based ionic hybrid was prepared by combining the divalent ionic liquid (IL) cation of 1,1′-(butane-1,4-diyl)-bis(3-methylimidazolium) with the Keggin-structured V-containing heteropolyanion, and characterized by 1H NMR, FT-IR, ESI-MS, XRD, SEM, TG, BET surface area, melting point, and elemental analysis. Its catalytic activity was evaluated in the hydroxylation of benzene with aqueous H 2O 2, including the testing of the influence of organic cations, catalytic reusability and optimization of reaction conditions. This hybrid is characterized to be semi-amorphous nanoparticles with a IL-like composition. The hybrid catalyst leads to the liquid–solid biphasic reaction system for hydroxylation of benzene with H 2O 2, presenting such advantages as high catalytic activity, convenient recovery, and steady reuse. The strong ionic interaction between the divalent IL cation and the heteropolyanion is responsible for the catalyst's solid nature and insolubility, and moreover, the bulk-type catalysis involving the V 5+/V 4+ redox pairs as active centers accounts for the hybrid's excellent catalytic performance.

Bicomponent VO 2-defects/MWCNT catalyst for hydroxylation of benzene to phenol: Promoter effect of defects on catalytic performance

A novel bicomponent catalyst, VO 2 supported on multi-walled carbon nanotubes (MWCNTs) with defects as promoter (VO 2-defects/MWCNTs) was synthesized for the hydroxylation of benzene to phenol. In the bicomponent system, VO 2 nanoparticles with 2–10 nm were prepared by the spontaneous redox between V 5+ and defects of MWCNTs. Moreover, defects of MWCNTs were firstly used as promoters for preventing the oxidation of phenol and transferring electrons in the catalysis. Thus, compared with other vanadium catalysts, VO 2-defects/MWCNTs show excellent catalytic performance for the hydroxylation of benzene to phenol, which indicates defects as promoter are quite promising for catalyzing the hydroxylation of benzene.

Long Chain Aliphatic Amine-Modified Heteropolyacid Catalysts for Hydroxylation of Benzene to Phenol with Molecular Oxygen

Organic-inorganic hybrid catalysts were prepared by combining laurylamine (or octadecylamine) and molybdovanadophosphoric acid, and their catalytic performance for the hydroxylation of benzene to phenol was evaluated using molecular oxygen as the oxidant in a pressured batch reactor. The laurylamine-modified heteropolyacid catalyst with a 4:1 molar ratio for the two moieties exhibited a much higher yield of phenol (11.5%) than that of the neat heteropolyacid H5PMo10V2O40 (3.9%). We discuss the promotional effect of the long chain aliphatic amines with regards to the interaction between the amine and the heteropolyacid framework, and we also discuss the “pseudo-liquid phase” behavior of the heteropolyacid.