Showing papers on "Benzaldehyde published in 2013"
TL;DR: Carbon quantum dots (CQDs) can function as an effective near infrared (NIR) light driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde with high selectivity and conversion under NIR light irradiation.
Abstract: Selective oxidation of alcohols is a fundamental and significant transformation for the large-scale production of fine chemicals, UV and visible light driven photocatalytic systems for alcohol oxidation have been developed, however, the long wavelength near infrared (NIR) and infrared (IR) light have not yet fully utilized by the present photocatalytic systems. Herein, we reported carbon quantum dots (CQDs) can function as an effective near infrared (NIR) light driven photocatalyst for the selective oxidation of benzyl alcohol to benzaldehyde. Based on the NIR light driven photo-induced electron transfer property and its photocatalytic activity for H2O2 decomposition, this metal-free catalyst could realize the transformation from benzyl alcohol to benzaldehyde with high selectivity (100%) and conversion (92%) under NIR light irradiation. HO˙ is the main active oxygen specie in benzyl alcohol selective oxidative reaction confirmed by terephthalic acid photoluminescence probing assay (TA-PL), selecting toluene as the substrate. Such metal-free photocatalytic system also selectively converts other alcohol substrates to their corresponding aldehydes with high conversion, demonstrating a potential application of accessing traditional alcohol oxidation chemistry.
267 citations
TL;DR: In this paper, the role of active species during selective oxidation of benzyl alcohol under visible light and the design of novel visible light active photocatalysts for selective oxidization of alcohol was investigated.
Abstract: In this study we propose several criteria for semiconductor photocatalysts suitable for visible light driven selective oxidation of BA to BAD by employing several literature-reported photocatalysts (P25, g-C 3 N 4 , In(OH) x S y , Bi 3 O 4 Br, BiOBr and Cu 2 O) to oxidize BA under visible light, and then demonstrate that the selectivity of photocatalytic oxidation of benzyl alcohol is highly depended on the position of valence band of semiconductors and Bi 12 O 17 Cl 2 nanobelts could efficiently and selectively oxidize benzyl alcohol into benzaldehyde under visible light via direct hole oxidation. Although the presence of molecular oxygen and the generation of superoxide radicals are important for the selective oxidation of benzyl alcohol, the exact role of molecular oxygen is merely to trap photogenerated electrons to produce superoxide radicals during Bi 12 O 17 Cl 2 photocatalysis, which could inhibit the recombination of photogenerated charge carries, but might not be involved in the alcohol oxidation directly. The role of molecular oxygen during Bi 12 O 17 Cl 2 photocatalysis was found to be different from those of TiO 2 and g-C 3 N 4 previously reported. This study provides new physical insights for the roles of active species during selective oxidation of alcohol under visible light and the design of novel visible light active photocatalysts for selective oxidation of alcohol.
264 citations
TL;DR: In this paper, the performance of Palladium catalysts on different carbon supports is investigated in the solvent-free aerobic oxidation of aromatic alcohols using molecular oxygen as oxidant, and the superior reactivity of Pd/graphene is attributed to the promotion role of graphene support in the adsorption of reactant alcohol and oxygen.
Abstract: Palladium catalysts supported on different carbon materials, i.e. graphene, carbon nanotube and activated carbon, have been prepared by improved wet impregnation and employed in the solvent-free aerobic oxidation of aromatic alcohols using molecular oxygen as oxidant. High catalytic activity as well as high selectivity to corresponding carbonyl compounds can be obtained on Pd/graphene. Typically, an extremely high turnover frequency of 30,137 mol/h molPd is observed in the aerobic oxidation of benzyl alcohol to benzaldehyde using Pd/graphene as catalyst. Palladium catalysts on different carbon supports are fully characterized by a series of techniques, e.g. Raman, XRD, SEM, TEM, TG, XPS, FTIR spectra of benzyl alcohol adsorption and O2-TPD. Based on the catalytic and characterization results, the superior reactivity of Pd/graphene in the aerobic oxidation of aromatic alcohols is attributed to the promotion role of graphene support in the adsorption of reactant alcohol and oxygen.
142 citations
TL;DR: In this article, the catalytic potential of various protic acids has been assessed for the one pot tandem condensation-cyclisation reaction involving an aldehyde, an amine, and thioglycolic acid to form 2,3-disubstituted thiazolidin-4-ones.
97 citations
TL;DR: A possible mechanism with Au-Pd nanoparticles as the active sites has been proposed, illustrating that the oxidation of benzyl alcohol can proceed through the cooperation between the Au- Pd nanoalloys and the base/acid sites on the surface of the support.
Abstract: Au–Pd nanoalloys supported on Mg–Al mixed metal oxides prepared using sol-immobilisation are found to be highly efficient and reusable catalysts for the solvent-free oxidation of benzyl alcohol using molecular oxygen under low pressure. When using this support alloying Pd with Au resulted in an increase in both activity and selectivity to benzaldehyde and moreover an improved resistance to catalyst deactivation compared with the monometallic Pd and Au catalysts. The turnover number for the Au/Pd 1 : 1 molar ratio catalyst achieved 13 000 after 240 min and the selectivity to benzaldehyde was maintained at 93%; this high catalytic activity can be retained in full after three successive uses. The ensemble and electronic effect of Au–Pd nanoalloys were studied by IR spectroscopy using CO chemisorption, XPS and HRTEM. Moreover, the bifunctional nature of the acid–base MgAl-MMO support was found to be important as the acid sites are considered to be responsible for the improvement of catalytic activity; while, the basic sites gave rise to high selectivity. A possible mechanism with Au–Pd nanoparticles as the active sites has been proposed, illustrating that the oxidation of benzyl alcohol can proceed through the cooperation between the Au–Pd nanoalloys and the base/acid sites on the surface of the support.
86 citations
TL;DR: In this paper, a co-reduction method was used to obtain Colloidal Au-Ag alloy nanoparticles with various Ag/Au molar ratios and characterized by UV-vis, TEM, and XPS.
74 citations
TL;DR: The thermal decompositions of furfural and benzaldehyde have been studied in a heated microtubular flow reactor in a pulsed, heated SiC reactor and the initial steps in the thermal decomposition have been identified.
Abstract: The thermal decompositions of furfural and benzaldehyde have been studied in a heated microtubular flow reactor. The pyrolysis experiments were carried out by passing a dilute mixture of the aromatic aldehydes (roughly 0.1%–1%) entrained in a stream of buffer gas (either He or Ar) through a pulsed, heated SiC reactor that is 2–3 cm long and 1 mm in diameter. Typical pressures in the reactor are 75–150 Torr with the SiC tube wall temperature in the range of 1200–1800 K. Characteristic residence times in the reactor are 100–200 μsec after which the gas mixture emerges as a skimmed molecular beam at a pressure of approximately 10 μTorr. Products were detected using matrix infrared absorption spectroscopy, 118.2 nm (10.487 eV) photoionization mass spectroscopy and resonance enhanced multiphoton ionization. The initial steps in the thermal decomposition of furfural and benzaldehyde have been identified. Furfural undergoes unimolecular decomposition to furan + CO: C4H3O–CHO (+ M) → CO + C4H4O. Sequential decomposition of furan leads to the production of HC≡CH, CH2CO, CH3C≡CH, CO, HCCCH2, and H atoms. In contrast, benzaldehyde resists decomposition until higher temperatures when it fragments to phenyl radical plus H atoms and CO: C6H5CHO (+ M) → C6H5CO + H → C6H5 + CO + H. The H atoms trigger a chain reaction by attacking C6H5CHO: H + C6H5CHO → [C6H6CHO]* → C6H6 + CO + H. The net result is the decomposition of benzaldehyde to produce benzene and CO.
72 citations
TL;DR: In this article, the technical feasibility of selective photocatalytic oxidation of benzyl alcohol to benzaldehyde, in aqueous solutions, in presence of cupric ions has been investigated in a solar pilot plant with compound parabolic collectors.
Abstract: The technical feasibility of selective photocatalytic oxidation of benzyl alcohol to benzaldehyde, in aqueous solutions, in presence of cupric ions has been investigated in a solar pilot plant with Compound Parabolic Collectors. Aldrich (pure anatase) and P25 Degussa TiO2 have been used as photocatalysts. The influences of cupric species concentrations, solar irradiance and temperature are discussed too. The oxidation rates were strongly influenced by the initial cupric ions concentration, incident solar irradiance and temperatures.
The best results found, in terms of yields and selectivities to benzaldehyde under acidic conditions were higher than 50% and 60%, respectively, under acidic conditions.
Under deaerated conditions, the presence of reduced copper species was proved by XPS analysis. The results indicated that, at the end of the process, cupric species can be easily regenerated and reused, through a re-oxidation of reduced copper, produced during the photolytic run, with air or oxygen in dark conditions.
A figure-of-merit (ACM), proposed by the International Union of Pure and Applied Chemistry (IUPAC) and based on the collector area, has been estimated, under the proposed conditions, with the aim to provide a direct link to the solar-energy efficiency independently of the nature of the system. Generally speaking, it can be considered that the lower ACM values the higher the system efficiency.
70 citations
TL;DR: In this article, a 0.5 m H 2 SO 4 solution was used to in situ synthesis of new inhibitor at different temperatures employing electrochemical, weight loss, quantum chemical studies and optical microscopy.
70 citations
TL;DR: A special modification of the Mannich reaction is the Betti reaction as mentioned in this paper, in which formaldehyde is replaced by an aromatic compound, the secondary amine by ammonia, and the acid acid by an electron-rich compound such as 1- or 2-naphthol.
63 citations
TL;DR: In this article, the amino-functionalised metal-organic framework, MIL-101(Al)-NH2, was synthesized by using a solvothermal method and employed as a bifunctional acid-base catalyst for a one-pot, sequential deacetalization-Knoevenagel condensation reaction.
Abstract: The amino-functionalised metal–organic framework, MIL-101(Al)-NH2, has been synthesized by using a solvothermal method and employed as a bifunctional acid–base catalyst for a one-pot, sequential deacetalization–Knoevenagel condensation reaction. In preliminary studies, the abilities of MIL-101(Al)-NH2 to serve as an acid and base catalyst were explored separately by two typical acid- and base-catalysed reaction, that is, deacetalization of benzaldehyde dimethylacetal and Knoevenagel condensation of benzaldehyde with malononitrile. MIL-101(Al)-NH2 was found to catalyse each of these reactions with high efficiency. MIL-101(Al)-NH2 was then employed as a catalyst for the one-pot sequential deacetalization–Knoevenagel condensation reaction between benzaldehyde dimethylacetal and malononitrile. Benzylidenemalononitrile as the final product was successfully generated with a high yield via benzaldehyde over MIL-101(Al)-NH2. In addition, the catalytic ability of MIL-101(Al)-NH2 was demonstrated to be superior to those of conventional heterogeneous, homogeneous as well as other functionalised metal–organic framework catalysts. Finally, the results show that MIL-101(Al)-NH2 can be reused as a catalyst for this process without significant loss of its activity.
TL;DR: Detailed aberration corrected STEM-XEDS analysis confirmed that the supported particles are indeed Au-Pd-Pt ternary alloys, but also identified composition fluctuations from particle-to-particle which vary systematically with nanoparticle size.
Abstract: Trimetallic Au–Pd–Pt nanoparticles have been supported on activated carbon by the sol-immobilisation method. They are found to be highly active and selective catalysts for the solvent-free aerobic oxidation of benzyl alcohol. The addition of Pt promotes the selectivity to the desired product benzaldehyde at the expense of toluene formation. Detailed aberration corrected STEM-XEDS analysis confirmed that the supported particles are indeed Au–Pd–Pt ternary alloys, but also identified composition fluctuations from particle-to-particle which vary systematically with nanoparticle size.
TL;DR: In this article, the shoulder yoke effect was introduced to describe the load-spreading ability of such an ancient device and the coordination geometry of copper(II)-salen-type Schiff base complexes.
Abstract: Mononuclear copper(II) salen-type Schiff base complexes, CuIIL1–5 [H2L1 to H2L5 = tetradentate N,N,O,O ligands derived from 2-hydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 3,5-dibromo-2-hydroxybenzaldehyde, 2-hydroxy-5-nitrobenzaldehyde, 5-chloro-2-hydroxybenzaldehyde and 1,3-bis(3-aminopropyl)tetramethyldisiloxane, respectively] were prepared in situ in the presence of a copper(II) salt or by direct complexation between a copper(II) salt and a presynthesised Schiff base. The compounds {CuL1, CuL1·0.5Py, CuL2·0.375CH2Cl2, (CuL3)[Cu(4-Me-Py)4Cl]Cl·2H2O, CuL4, CuL4·CHCl3 and CuL5, as well as the isolated ligand H2L3} were characterised by elemental analysis, spectroscopic methods (IR, UV/Vis, 1H NMR, EPR) and X-ray crystallography. The formation of a 12-membered central chelate ring in these complexes is effected by the tetramethyldisiloxane unit, which separates the aliphatic chains, thus significantly reducing the mechanical strain in such a chelate ring. We dub this a “shoulder yoke effect” by analogy with the load-spreading ability of such an ancient device. The coordination geometry of copper(II) in CuIIL1–5 can be described as tetrahedrally distorted square-planar. Maximum tetrahedral distortion of the coordination geometry expressed by the parameter τ4 was observed for CuL1 (0.460), while distortion was minimal for the two crystallographically independent molecules of CuL2 (0.219 and 0.284). The Si–O–Si bond angle varies markedly between 169.75(2)° for CuL1 and 154.2(3)° for CuL4·CHCl3. Charge-density and DFT calculations on CuL1 indicate high ionic character of the Si–O bonds in the tetramethyldisiloxane fragment. The new copper(II) complexes bearing the disiloxane moiety have been shown to act as catalyst precursors for the aerobic oxidation of benzyl alcohol to benzaldehyde mediated by the TEMPO radical, reaching yields and TONs up to 99 % and 990, respectively, under mild and environmentally friendly conditions (50 °C; MeCN/H2O, 1:1).
TL;DR: In this article, an environmentally benign solvent free oxidation of alcohols catalyzed by mono transition metal-substituted Keggin-phosphomolybdates, PMo 11 M (M = Co, Mn, Ni) using hydrogen peroxide was carried out under mild conditions.
Abstract: Traditional procedures for synthesis of carbonyl compounds suffer from a lack of selectivity, use of organic solvents, toxicity of the reagents, and waste production. As a cleaner alternative, an environmentally benign solvent free oxidation of alcohols catalyzed by mono transition metal-substituted Keggin-phosphomolybdates, PMo 11 M (M = Co, Mn, Ni) using hydrogen peroxide was carried out under mild conditions. The influence of different parameters such as mole ratio of benzyl alcohol to H 2 O 2 , amount of the catalyst, reaction time and reaction temperature on oxidation of benzyl alcohol was investigated. Further, oxidation of various alcohols such as cyclopentanol, 1-hexanol and 1-octanol with PMo 11 M was carried out under optimized conditions. The catalytic activity of recycled catalysts was also evaluated and it was found that catalysts are stable under present reaction conditions. All the catalysts are very much efficient, especially in terms of % selectivity of the desire product.
TL;DR: In this paper, Nitrogen-doped carbon nanotubes (N-CNTs) were employed as carbon-based catalysts for selective oxidation of benzyl alcohol to benzaldehyde with molecular oxygen as the terminal oxidant under mild reaction conditions.
TL;DR: In this paper, surface plasmon excitation of supported gold nanoparticles in the presence of H2O2 leads to selective oxidation of sec-phenethyl and benzyl alcohols to the carbonyl products acetophenone and benzaldehyde, respectively, in the absence of additional solvents.
Abstract: Surface plasmon excitation of supported gold nanoparticles in the presence of H2O2 leads to selective oxidation of sec-phenethyl and benzyl alcohols to the carbonyl products acetophenone and benzaldehyde, respectively, in the absence of additional solvents. Light-emitting diodes are compared with microwave irradiation as excitation sources. Hydrotalcite, ZnO, and Al2O3 have been chosen as the solid supports. The overall efficiency of the alcohol oxidation was found to be largely dependent on the nature of the support, with hydrotalcite-derived nanocomposites giving the highest conversions to product, yielding 90% acetophenone after 40 min of LED irradiation. The mechanism for plasmon-mediated alcohol oxidation is believed to involve a significant contribution from the support itself, with adsorption of the alcohol substrate and progression of the oxidation reaction being largely facilitated by the basicity of the support used.
TL;DR: With the suitable selection of a gold catalyst as well as the appropriate control of the reaction conditions, various new gold-catalyzed cyclizations of 2-alkynyl benzaldehyde with acyclic or cyclic vinyl ethers have been developed.
Abstract: With the suitable selection of a gold catalyst as well as the appropriate control of the reaction conditions, various new gold-catalyzed cyclizations of 2-alkynyl benzaldehyde with acyclic or cyclic vinyl ethers have been developed. Acetal-tethered dihydronaphthalene and isochromenes were obtained from the reactions of 2-alkynyl benzaldehydes with acyclic vinyl ethers under mild conditions. And, more interestingly, the gold-catalyzed reactions of 2-alkynyl benzaldehyde with a cyclic vinyl ether afforded the bicyclo[2.2.2]octane derivative involving two molecules of cyclic vinyl ethers. These products contain interesting substructures that have been found in many biologically active molecules and natural products. In addition, a gold-catalyzed homo-dimerization of 2-phenylethynyl benzaldehyde 1a was observed when the reaction was carried out in the absence of vinyl ether, affording a set of separable diastereomeric products. Plausible mechanisms for these transformations are discussed; a gold-containing benzopyrylium was regarded as the crucial intermediate by which a number of these new transformations took place.
TL;DR: A series of mixed nano-metal oxides of Cu-Ni-Co on γ-alumina with different metal loadings have been synthesized through the ultrasonic cavitation-impregnation method as discussed by the authors.
TL;DR: In this article, phase-pure MoV(TeNb) M1 oxide catalysts were studied to gain insight into the multiple catalytic functions of the surface of the M1 structure.
Abstract: Propane oxidation at 653–673 K and benzyl alcohol oxidation at 393 K over phase-pure MoV(TeNb) M1 oxide catalysts were studied to gain insight into the multiple catalytic functions of the surface of the M1 structure. Electron microscopy and X-ray diffraction confirmed the phase purity of the M1 catalysts. Propane oxidation yields acrylic acid via propene as intermediate, while benzyl alcohol oxidation gives benzaldehyde, benzoic acid, benzyl benzoate, and toluene. The consumption rates of benzyl alcohol and propane level in the same range despite huge difference in reaction temperature, suggesting high activity of M1 for alcohol oxidation. Metal–oxygen sites on the M1 surface are responsible for the conversion of the two reactants. However, different types of active sites and reaction mechanisms may be involved. Omitting Te and Nb from the M1 framework eliminates acrylic acid selectivity in propane oxidation, while the product distribution in benzyl alcohol oxidation remains unchanged. The results suggest...
TL;DR: In this article, the authors applied the Langmuir-Hinshelwood and power-law kinetic models to describe the experimental results of catalytic oxidation of benzyl alcohol with H2O2 over heterogeneous bio-reduced Au/TS-1 catalysts.
Abstract: In this paper, the kinetics and mechanism of oxidation of benzyl alcohol with H2O2 over heterogeneous bio-reduced Au/TS-1 catalysts have been reported after eliminating mass transfer resistances. Langmuir–Hinshelwood and power-law kinetic models are applied to describe the experimental results of the catalytic oxidation. By fitting the kinetic data using the power-rate law model, the orders of the reaction with respect to benzyl alcohol, H2O2, benzaldehyde and catalyst were found to be 0.55, 0.22, −0.35 and 1.06, respectively, with an activation energy of 38.2 kJ mol−1 from an Arrhenius plot. These fractional orders indicate that the species were adsorbed on the catalyst surface leading to the product, benzaldehyde. Furthermore, the reaction mechanism derived from the Langmuir–Hinshelwood model is proposed; it gives a reasonable description of the oxidation rate, following a rate expression:. r = 0.0119 × [ BzOH ] [ H 2 O 2 ] ( 1 + 2.222 × [ BzOH ] + 2.330 × [ H 2 O 2 ] + 4.769 × [ BzH ] ) 2 ( mol L − 1 g cat − 1 s − 1 ) .
TL;DR: This procedure contains an Ullmann-type reaction and provides an efficient method to construct fused tetracyclic heterocycles.
Abstract: The treatment of 2-amino-N′-arylbenzohydrazide and o-halogenated benzaldehyde in the presence of CuBr and Cs2CO3 gave 5-arylindazolo[3,2-b]quinazolin-7(5H)-one in high yields. This procedure contains an Ullmann-type reaction and provides an efficient method to construct fused tetracyclic heterocycles.
TL;DR: Using O2 as the oxidizing agent, bulk gold catalyzes the following types of reactions in organic solvents at 45-90 °C: (1) the conversion of amines to imines (RCH2)2NH → RCH2NCHR), (2) the oxidation of benzyl alcohol to benzaldehyde, (3) the reaction of isocyanides with primary amines, giving carbodiimides [CN−R + H2N−R′ → R′−NCN-R], and (4) the reactions of
TL;DR: In this paper, 2-Hydroxypropyl-β-cyclodextrin was immobilized onto cellulose with epichlorohydrin as a cross-linker, which was used to mediate synthesis of benzaldehyde in aqueous solution.
Abstract: 2-Hydroxypropyl-β-cyclodextrin was immobilized onto cellulose with epichlorohydrin as a cross-linker. The obtained polymer, as biomimetic catalyst, was used to mediate synthesis of benzaldehyde in aqueous solution. The functionalized mimetic enzyme played a crucial role on catalytic oxidation of cinnamaldehyde with remarkable substrate conversion and product selectivity. Synergistic effect based on weak interactions between the polymer and the substrate results in significant promotion of the catalytic performance. The catalyst could be recycled without apparent loss of the original activity.
TL;DR: Carbon nanotube (CNT)-TiO2 nanohybrids with the potential to control the phase of an emulsion were successfully developed with a simple yet efficient method.
Abstract: Mix it up: Carbon nanotube (CNT)-TiO2 nanohybrids with the potential to control the phase of an emulsion were successfully developed with a simple yet efficient method. When ruthenium was deposited on these CNT-TiO2 nanohybrid supports, they demonstrated catalytic potential for the selective oxidation of benzyl alcohol to benzaldehyde. The relationship between the emulsion properties and the catalytic mechanism is also discussed.
01 Jan 2013
TL;DR: An improved model for the oxidation of toluene was developed based on recent theoretical studies of the elementary steps involved in the low-temperature chemistry of this molecule and simulation results showed that the reactivity of the alkane is inhibited by the presence of benzene and, to a larger extent, toLUene.
Abstract: The oxidation of two blends, benzene/n-decane and toluene/n-decane, was studied in a jet-stirred reactor with gas chromatography analysis (temperatures from 500 to 1100 K, atmospheric pressure, stoichiometric mixtures). The studied hydrocarbon mixtures contained 75% of aromatics in order to highlight the chemistry of the low-temperature oxidation of these two aromatic compounds which have a very low reactivity compared to large alkanes. The difference of behavior between the two aromatic reactants is highly pronounced concerning the formation of derived aromatic products below 800 K. In the case of benzene, only phenol could be quantified. In the case of toluene, significant amounts of benzaldehyde, benzene, and cresols were also formed, as well as several heavy aromatic products such as bibenzyl, phenylbenzylether, methylphenylbenzylether, and ethylphenylphenol. A comparison with results obtained with neat n-decane showed that the reactivity of the alkane is inhibited by the presence of benzene and, to a larger extent, toluene. An improved model for the oxidation of toluene was developed based on recent theoretical studies of the elementary steps involved in the low-temperature chemistry of this molecule. Simulations using this model were successfully compared with the obtained experimental results.
TL;DR: A series of polyoxometalate (POM)-based amphiphilic catalysts were prepared via functionalization of the V-containing Keggin POM H4PMo11VO40 by cationic surfactants with different carbon-chain lengths as discussed by the authors.
Abstract: A series of polyoxometalate (POM)-based amphiphilic catalysts were prepared via functionalization of the V-containing Keggin POM H4PMo11VO40 by cationic surfactants with different carbon-chain lengths. These prepared catalysts were systematically characterized by Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (NMR), thermogravimetric (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, and X-ray diffraction (XRD) techniques as well as by the elemental analysis. Their catalytic activities were evaluated in the selective oxidation of benzyl alcohol to benzaldehyde by H2O2 under organic solvent-free conditions. Among the catalysts investigated, the amphiphilic (ODA)4PMo11VO40 (ODA: octadecylmethylammonium) shows the highest catalytic efficiency for the selective oxidation. The high activity and selectivity of the prepared (ODA)4PMo11VO40 are probably related to its amphiphilic property. A maximum conversion of benzyl alcohol is 60.6% with a selec...
TL;DR: In the solvent free oxidation of benzyl alcohol, using supported gold-palladium nanoalloys, toluene is often one of major by-products and it is formed by the disproportionation of Benzyl alcohol and oxidative dehydrogenation to form benzaldehyde.
Abstract: In the solvent free oxidation of benzyl alcohol, using supported gold–palladium nanoalloys, toluene is often one of major by-products and it is formed by the disproportionation of benzyl alcohol. Gold–palladium catalysts on acidic supports promote both the disproportionation of benzyl alcohol and oxidative dehydrogenation to form benzaldehyde. Basic supports completely switch off disproportionation and the gold–palladium nanoparticles catalyse the oxidative dehydrogenation reaction exclusively. In an attempt to provide further details on the course of these reactions, we have utilized in situ ATR-IR, in situ DRIFT and inelastic neutron scattering spectroscopic methods, and in this article we present the results of these in situ spectroscopic studies.
TL;DR: A series of vanadium(V) complexes with chiral tridentate Schiff base ligands, obtained by the single condensation of R(−)-phenylglycinol with salicylaldehyde and its derivatives, were prepared.
TL;DR: A series of 1-alkyl (or acetic acid)-3-methylimidazolium-metal chloride ionic liquids such as AmimBr Cl, BF 4 -MCl x (A,=ethyl, butyl, acetic acids and benzyl radicals; M,=Fe, Cu, Sn, Mn, Ni, Co and Zn; x ǫ = 2, 3 and 4) and Et 3 NHCl-FeCl 3 were prepared by conventional method.
TL;DR: In this paper, a CdS/TiO2 photocatalyst modified with a Pd co-catalyst was applied to a photocatalytic system for the selective dehydrogenation of benzyl alcohol to benzaldehyde with high selectivity (>99%) accompanied by the formation of H2 in aqueous solution under visible-light irradiation.