Showing papers on "Cyclohexanone published in 2019"
TL;DR: In this article, the meso-Fe2O3-supported single-atom Pt with a loading of x wt% (xPt1/meso-fe 2O3, x pt1, x PtNP, x q q q, q q = 0.08, 0.15, and 0.25) catalysts were synthesized via a polyvinyl alcohol-protected reduction route.
Abstract: Single-atom catalysts are a kind of promising catalytic materials that can use the precious metal more efficiently. The KIT-6-templaing method was adopted to obtain three-dimensionally ordered mesoporous iron oxide (meso-Fe2O3). The meso-Fe2O3-supported single-atom Pt with a loading of x wt% (xPt1/meso-Fe2O3, x = 0.08, 0.15, and 0.25) catalysts were synthesized via a polyvinyl alcohol-protected reduction route. The 0.25 Pt1/meso-Fe2O3 sample showed much better catalytic activity than the meso-Fe2O3-supported Pt nanoparticle (0.25 PtNP/meso-Fe2O3) sample for benzene combustion, with the temperatures T10%, T50%, and T90% (corresponding to benzene conversions of 10, 50, and 90%) were 164, 186, and 198 °C at a space velocity of 20,000 mL/(g h), respectively. The TOFPt (2.69 s−1) obtained over 0.25 Pt1/meso-Fe2O3 at 160 °C was much higher than that (1.16 s−1) obtained over the 0.25 PtNP/meso-Fe2O3 sample at 160 °C. Furthermore, the 0.25 Pt1/meso-Fe2O3 and 0.15Pt1/meso-Fe2O3 samples exhibited better water-resistant ability than the 0.25 PtNP/meso-Fe2O3 sample, which was possibly due to formation of the active radicals and decomposition of carbonates in the presence of moisture. In situ DRIFTS results demonstrate that the phenolate and benzoquinone as well as cyclohexanone and maleate were the main intermediates in the oxidation of benzene. The good stability of the 0.15Pt1/meso-Fe2O3 and 0.25 Pt1/meso-Fe2O3 samples was associated with the strong interaction between Pt and meso-Fe2O3.
144 citations
TL;DR: In this paper, a magnetically separable bimetallic ZnO and Co nanoparticles (NPs) deposited on N-doped carbon nanotubes (ZnO/Co@N-CNTs) were synthesized by the direct calcination of the bimetal Zn/Co zeolitic imidazolate framework (ZN/Co-ZIF) for the effective hydrogenation and hydrodeoxygenation (HD) of lignin and its derived species.
62 citations
TL;DR: Product selectivity in aqueous phase phenol hydrogenation on well-defined supported Pd nanostructures (spheres, cubes, and octahedra) was studied using defined experiments and density functional properties as discussed by the authors.
Abstract: Product selectivity in aqueous phase phenol hydrogenation on well-defined supported Pd nanostructures (spheres, cubes, and octahedra) was studied using defined experiments and density functional th...
54 citations
TL;DR: In this paper, an amorphous and mesoporous zirconium phosphonate catalyst (Zr-DTMP) was successfully designed and synthesized by the simple assembly of ZrCl4 and diethylene triaminepenta(methylene phosphonic acid) (DTMP).
48 citations
TL;DR: In this article, a co-impregnation method was used to characterize the catalysts of guaiacol as a model compound over molybdenum (Mo), tungsten (W), and tantalum (Ta) modified nickel catalysts supported on Al2O3, ZrO2, TiO2 and SiO2.
44 citations
TL;DR: Au nanoclusters encapsulated in an MCM-22 zeolite are highly active for the selective aerobic oxidation of cyclohexane to KA-oil.
43 citations
TL;DR: In this paper, the feasibility of using different types of alcohols, primary (methanol, ethanol, 1-propanol, and 1-butanol), as a substitute for hydrogen gas in the guaiacol hydrodeoxygenation process was examined.
41 citations
01 Jan 2019
TL;DR: This study highlights a new pathway for preparing N-doped porous carbon materials using biomass waste as the precursor material, and subsequently fabricating precious metal-modified catalysts with excellent catalytic performance for sustainable and green catalysis.
Abstract: Use of renewable raw materials for fabrication catalysts with excellent catalytic performance is of considerable importance for sustainable chemistry. Here, biowaste soybean curd residue (SCR) was used to prepare porous N-doped carbon materials (PNCM) via the carbonization method, and subsequently modified with small Pd nanoparticles (NPs) to generate the Pd/PNCM catalyst. Pd/PNCM was used for catalytic hydrogenation of phenol to cyclohexanone, as the latter is an important chemical intermediate that is usually produced under harsh reaction conditions. The Pd/PNCM catalyst can hydrogenate phenol to cyclohexanone in aqueous solution under mild reaction conditions with excellent catalytic performance. In addition, compared to commercial Pd/C, Pd/PNCM exhibits excellent catalytic performance and stability, which is attributed to the synergetic effects of N-doping of porous carbon supports and stabilization of ultra-small Pd NPs. Thus, this study highlights a new pathway for preparing N-doped porous carbon materials using biomass waste as the precursor material, and subsequently fabricating precious metal-modified catalysts with excellent catalytic performance for sustainable and green catalysis.
41 citations
TL;DR: In this paper, a pincer NHC precursors, CoCl2, and a base enabled efficient and high-yielding hydrogenation of a broad range of ketones and aldehydes.
37 citations
TL;DR: In this paper, the microstructure and surface properties of activated carbon (AC) were successfully turned by simply controlling the initial oxygen concentration during the calcination, the modified AC materials were doped with nitrogen and supported by Pd nanoparticles (NPs) to prepare Pd/N-doped porous carbon (Pd/CN) catalysts, and their catalytic performance in the phenol hydrogenation to cyclohexanone was evaluated.
Abstract: Herein, the microstructure and surface properties of activated carbon (AC) was successfully turned by simply controlling the initial oxygen concentration during the calcination, the modified AC materials were doped with nitrogen and supported by Pd nanoparticles (NPs) to prepare Pd/N-doped porous carbon (Pd/CN) catalysts, and their catalytic performance in the phenol hydrogenation to cyclohexanone was evaluated. The modification with trace oxygen can decrease the hydrophilicity of AC, leading to better dispersibility of the Pd/CN O catalyst in nonpolar reaction solvent (cyclohexane). Trace oxygen modification can increase the content of O-containing groups (C O) on the AC surface, promoting the interaction between Pd NPs and carrier, thus higher Pd dispersion. As a result, the modified Pd/CN catalyst (Pd/CN O) exhibits superior catalytic activity and stability than unmodified Pd/CN catalyst (Pd/CN-raw), with a phenol conversion increased from 84.1% to 99.6%. This work would aid the deep insights into the phenol hydrogenation over Pd/CN.
36 citations
TL;DR: In this paper, pyrolysis simulations of cyclohexanone with ReaxFF-MD were performed using LAMMPS and reactions analyses were carried out by ChemTrayzer code.
TL;DR: In this article, a new hafnium-based metal-organic coordination polymer (Hf-DTMP) was designed and prepared for the selective hydrogenation of biomass-derived 5-methylfurfural (HMF) into 2,5-bis(hydroxymethyl)furan via the Meerwein-Ponndorf-Verley (MPV) reaction.
Abstract: The catalytic transfer hydrogenation (CTH) pathway is a promising and appealing method for the selective hydrogenation of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-bis(hydroxymethyl)furan (BHMF) via the Meerwein–Ponndorf–Verley (MPV) reaction, in which the development of effective and economical catalysts is of great significance. Herein, this work designed and prepared a new hafnium-based metal–organic coordination polymer (Hf-DTMP) by the simple assembly of hafnium tetrachloride (HfCl4) and diethylene triaminepenta(methylene phosphonic acid) (DTMP). Comprehensive studies demonstrated that Hf-DTMP is an amorphous and mesoporous catalyst with a strong acid–base bifunctionality, and so, it displayed excellent catalytic activity for the CTH of HMF into BHMF with a high yield of 96.8% in 2-butanol (sBuOH) at a moderate reaction temperature of 130 °C for 4 h. In addition, Hf-DTMP exhibited good heterogeneity, reusability and stability, and it could be easily recovered from the reaction mixture by filtration and consecutively used for at least 5 recycles without a dramatic loss in catalytic activity. More gratifyingly, Hf-DTMP also showed superior universality for the CTH of 5-methylfurfural (MF), furfural (FF), levulinic acid (LA), ethyl levulinate (EL) and cyclohexanone (CHN) into the corresponding products with high yields, obviously indicating that it has tremendous potential for the selective hydrogenation of various biomass-derived carbonyl compounds.
TL;DR: In this paper, the cyclohexanone ammoximation production process was explored based on reaction kinetics in order to reduce its energy consumption and total annual cost, and the effects of reaction temperature, space time, and raw material ratios on the cycloencoder yield were analyzed.
TL;DR: In this paper, ZIF-derived N-doped carbon (CN) materials were modified by TiO2 nano-islands with oxygen vacancies (OV) through a sol-gel method and subsequent thermal treatment.
TL;DR: In this article, the photocatalytic oxidation of cyclohexane was carried out in acetonitrile (MeCN) solution of VOCl 2 under Xe lamp irradiation and pure O 2 atmosphere.
TL;DR: In this paper, the presence of Na alkaline additives (NaX, X = CO32, HCO3, or OH)-on Pd/Al2O3 was found to not only increase the phenol conversion rate from 8.3% to 99% but also increased cyclohexanone selectivity from 89% to 97% during continuous hydrogenation of phenol on a fixed bed reactor.
TL;DR: DFT calculations show that the presence of Ru (either as pure Ru or as a Ni-Ru alloy) reduces the energy barrier for phenol hydrogenation by close to 0.2 eV relative to pure Ni, and that theEnergy barrier is not as largely affected by the amount of Ru present, provided it is non-zero.
TL;DR: In this article, a chiral zirconium-based catalyst, DUT-67-Pro containing 8-connected Zr6-clusters is obtained by post synthetic functionalization of Zr 6O6(OH)2(TDC)4(HCOO)2 (DUT- 67, TDC = 2,5-thiophenedicarboxylate) with the chiral monocarboxylic acid, L -proline.
TL;DR: In this paper, first-row transition-metal silica coated magnetite nanoparticles (MNPs), Fe3O4@SiO2-M2+ [M]=Mn2+ (1), Co2+(2), Cu2+
TL;DR: In this article, the microstructure and properties of the Ti3+/TiO2 SMP were characterized by X-ray diffraction (XRD), UV-visible diffuse reflection (UV-Vis DRS), scanning electron microscopy (SEM), electron paramagnetic resonance (EPR), solid-state photoluminescence spectroscopy (PLS), and XPS.
TL;DR: In this article, a very stable catalyst, phosphotungstic acid (PTA) encapsulated in metal-organic framework UiO-66, was prepared by a simple one-pot solvothermal method.
Abstract: A very stable catalyst, phosphotungstic acid (PTA) encapsulated in metal–organic framework UiO-66, was prepared by a simple one-pot solvothermal method. Characterization results show that UiO-66 is quite stable in the catalyst preparation process, and PTA is encapsulated in the cavities of UiO-66 with good dispersity. The as-synthesized composite material exhibited good catalytic activity and excellent reusability for the green oxidation of cyclohexanone to adipic acid (AA). Under mild reaction conditions, the isolated yield of AA was as high as 80.3% without the introduction of any organic solvent or phase transfer agent. The excellent immobilization effect of UiO-66 for PTA is mainly because UiO-66 has a well matched window size to confine PTA molecule in its nanocages.
TL;DR: 5c can be a potential anticancer agent for early treatment of liver cancers and in vivo, 5c can effectively suppress the growth of HepG2 xenografts without apparent body weight changes.
Abstract: Novel hydroxyl-substituted double Schiff-base 4-piperidone/cyclohexanone derivatives, 3a–e, 4a–e, 5a–d, and 6a–c, were synthesized and fully characterized by 1H NMR, IR and elemental analysis. The ...
TL;DR: In this article, the role of vanadium nuclearity in catalytic oxidation of cyclohexane and cycloenhexanol was investigated in detail by theoretical DFT methods, which is different from those usually accepted for the Fenton or Fenton-like systems and it includes (i) coordination of H2O2 to the catalyst molecule, (ii) proton transfer from ligated H 2O 2 to the methoxy ligand and elimination of the formed methanol molecule and (iii) coordination, followed by HO-OH bond cleavage to give HO�
Abstract: The mono-, bi- and tri-nuclear oxidovanadium(V) complexes [VO(OEt)(L1)] (1), [{VO(OEt)(EtOH)}2(L2)] (2) and [{VO(OMe)(H2O)}3(L3)]·2H2O (3) (L1 = 2-hydroxy-(2-hydroxybenzylidene)benzohydrazide, L2 = bis(2-hydroxybenzylidene)terephthalohydrazide and L3 = tris(2-hydroxybenzylidene)benzene-1,3,5-tricarbohydrazide) (3 was synthesized for the first time) were used to investigate the role of vanadium nuclearity in the catalytic oxidation of cyclohexane and cyclohexanol. They are active homogeneous catalysts for the microwave-assisted neat peroxidative oxidation of cyclohexane (with aq. H2O2 to cyclohexanol and cyclohexanone) and cyclohexanol (with aq. tBuOOH to cyclohexanone). A mechanism of the HO˙ radical generation – the rate limiting step of the cyclohexane oxidation by H2O2 – was investigated in detail by theoretical DFT methods. The mechanism is different from those usually accepted for the Fenton or Fenton-like systems and it includes (i) coordination of H2O2 to the catalyst molecule, (ii) proton transfer from ligated H2O2 to the methoxy ligand and elimination of the formed methanol molecule and (iii) coordination of the second H2O2 molecule followed by HO–OH bond cleavage to give HO˙. The activation of the ligated H2O2 towards this cleavage is associated with the redox active nature of the ligand L in the catalyst molecule, which acts (instead of the metal) as the reducing agent of the H2O2 ligand.
TL;DR: In this article, a simple and cheap cobalt(II) 5,10,15,20-tetrakis(4-pyridyl)porphyrin (Co TPyP) was anchored onto nanoporous bar with thiol-functionalized silica (npb-SiO2-SH).
TL;DR: In this article, a one-step aerobic oxidation of cyclohexane to prepare adipic acid, catalyzed by N-hydroxyphthalimide (NHPI) under promoter-and metal-free conditions is described.
TL;DR: In this article, a composite catalytic system of Pd/C-heteropoly acid was used for the selective hydrogenation of phenol to cyclohexanone under mild conditions.
Abstract: Cyclohexanone is an important intermediate in the manufacture of polyamides in chemical industry, but direct selective hydrogenation of phenol to cyclohexanone under mild conditions is a challenge. Hydrogenation of phenol to cyclohexanone has been investigated in the presence of the composite catalytic system of Pd/C-heteropoly acid. 100% conversion of phenol and 93.6% selectivity of cyclohexanone were achieved within 3 h under 80 °C and 1.0 MPa hydrogen pressure. It has been found that a synergetic effect of Pd/C and heteropoly acid enhanced the catalytic performance of the composite catalytic system which suppressed the hydrogenation of cyclohexanone to cyclohexanol.
TL;DR: In this paper, the authors have synthesized glutathione-protected Ag6 clusters via a facile green reaction route, transferred onto graphene oxide (GO) and exploit as catalyst for cyclohexane oxidation under ambient conditions.
Abstract: Metal clusters including those supported on graphene-based materials have attracted extensive research interest in the past decade allowing dissection of the interfaces, stability, electronic properties, and catalytic activities at an atomically precise scale. Here, we have synthesized glutathione-protected Ag6 clusters via a facile green reaction route, transferred onto graphene oxide (GO) and exploit as catalyst for cyclohexane oxidation under ambient conditions. High selectivity and high yields to produce cyclohexanone are attained with tert-butyl hydroperoxide (TBHP) as the oxidant in the oxygen-flowing atmosphere. Based on density functional theory calculations, it is demonstrated that both TBHP and oxygen interact with the GO-supported Ag6 clusters, giving rise to the peroxide structure and hence facilitating the catalytic oxidation of cyclohexane. It is interestingly found that the hydrogen-added hydroperoxyl (−OOH) brings forth largely decreased activation barrier for the O–O bond dissociation. Th...
TL;DR: In this paper, an aminoiron(III) porphyrin was used as a reusable heterogeneous catalyst for the oxidation of organic substrates, which proved to be a promising system for the efficient and selective oxidation of the organic substrate with 85-92% selectivity to the epoxide in the alkenes and 25-41% to the ketone in the cyclohexane.
TL;DR: Wang et al. as discussed by the authors reported a significantly improved cyclohexane conversion and KA oil selectivity under solar light irradiation by anew photothermal synergistic catalyst, which was prepared by loading Au nanoparticles (Au NPs) onto WO3 nanosheets (WO3 NSs) with simple ultrasonic method.
TL;DR: In this article, the synthesis and fluorescence properties of highly substituted bicyclic pryridine derivatives are described and significant results were observed, including the fluorescence spectroscopic data of compounds 1-4, 6-8, 11, 12, 14 and 15.
Abstract: The synthesis and fluorescence properties of highly substituted bicyclic pryridine derivatives are described. 2-Substituted-4-oxo-pyrido[2,3-d]pyrimidines 2–8 resulted from the acylation reaction of α-aminonicotinonitrile 1 with aroyl chlorides, diethyl malonate, morpholine-4-carboxylate, acetic anhydride or formic acid under solvent-free conditions. [4 + 2] Cyclocondensation and cycloaddition reactions of compound type 1 with formamide and ammonium thiocyanate tolerated the fused pyrimidines 9 and 11, respectively. Finally, the Friedlander-like reaction was applied for the synthesis of 1,8-naphthyridines 12–15 via reaction of compound 1 with cyclohexanone, dimedone, acetyl acetone and benzyl methyl ketone, respectively, under AlCl3 catalysis. The fluorescence spectroscopic data of compounds 1–4, 6–8, 11, 12, 14 and 15 measured and significant results were observed.