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Chinese Journal of Catalysis
2013, Vol. 34, No. 9
Online: 16 September 2013


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Liu and coworkers in their Article on pages 1635–1643 reported the preparation of phosphine-functionalized polystyrene microcapsule hundreds of microns in size using a microfluidic platform. After Pd immobilization, the microcapsule, which can be easily recovered, shows superior catalytic activity for Suzuki coupling reactions compared with the homogeneous Pd catalyst. Moreover, it can provide high catalyst density and good mechanical stability.

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Table of Contents for Vol. 34 No. 9 2013, 34 (9):  0-0.  Abstract ( 210 )   PDF (1057KB) ( 612 )

Research papers

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Preparation of microcapsule-supported Pd catalyst using a microfluidic platform Ying Liu, Yangcheng Lü, Guangsheng Luo 2013, 34 (9):  1635-1643.  DOI: 10.1016/S1872-2067(12)60630-5 Abstract ( 618 )   [Full Text(HTML)] () PDF (894KB) ( 706 )   A phosphine-functionalized polystyrene microcapsule with hundreds of microns in size was prepared using a microfluidic platform. The size distribution was narrow and the average size could be adjusted in the range 300-400 μm. The morphology and composition of the microcapsules were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and inductively coupled plasma atomic emission spectroscopy. The results verified the effectiveness of the strategy we proposed for preparing uniform microcapsules with stable Pd immobilization. A Suzuki coupling reaction between aryl halides and phenylboronic acid was used as the model to evaluate their catalytic activity after Pd(PPh3)4 immobilized onto the microcapsule. It was found that the catalytic activity of microcapsule-supported Pd was always higher than that of the corresponding homogeneous catalyst, and was similar with that of the literature reported microcapsule-supported catalyst with about 7-8 μm particle size. Microcapsule-supported Pd with microcapsules of hundreds of microns in size, being easy to recover, showed good reusability and undetected active species loss, its productivity effect and controllability of the microcapsule-supported Pd catalyst were also expected to benefit from continuous preparation using the microfluidic platform. Moreover, they could be potentially exploited in a fixed-bed reactor with high catalyst density and good mechanical stability.

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Copper-catalyzed oxidative amidation of dibenzylamines via C-H bond activation Jinjin Hu, Xiujin Zuo, Hanmin Huang 2013, 34 (9):  1644-1650.  DOI: 10.1016/S1872-2067(12)60617-2 Abstract ( 532 )   [Full Text(HTML)] () PDF (459KB) ( 577 )   A new method has been developed for the oxidative amidation of dibenzylamines to construct N-benzylbenzamides via C-H bond activation. This new method allows for the formation of two amide products from a single dibenzylamine starting material in good yields using CuBr as a catalyst and diacetoxyiodobenzene as an oxidant under mild reaction conditions. The catalyst system performed efficiently, and this study represents the first reported use of diacetoxyiodobenzene as an oxidant for the oxidative amidation of dibenzylamines to the corresponding N-benzylbenzamides.

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Substrate-promoted copper-catalyzed N-arylation of amino alcohols with aryl iodides in water Ming Jin, Dan Zhao, Guozhen He, Yao Tong, Shiqing Han 2013, 34 (9):  1651-1655.  DOI: 10.1016/S1872-2067(12)60623-8 Abstract ( 470 )   [Full Text(HTML)] () PDF (439KB) ( 889 )   An efficient method has been developed for the N-arylation of a variety of water-soluble amino alcohols (1.2 mmol) with aryl iodides (1.0 mmol) in water under CuI-catalyzed conditions. The reaction was conducted via substrate-promoted action and did not require an additional ligand or phase-transfer catalyst, and afforded the desired N-aryl amines in acceptable to excellent yields (64%-93%) under mild reaction conditions with a small excess of the amino alcohol.

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Role of ReOx in Re-modified Rh/ZrO2 and Ir/ZrO2 catalysts in glycerol hydrogenolysis：Insights from first-principles study Jing Guan, Xiufang Chen, Gongming Peng, Xicheng Wang, Quan Cao, Zhenggang Lan, Xindong Mu 2013, 34 (9):  1656-1666.  DOI: 10.1016/S1872-2067(12)60626-3 Abstract ( 454 )   [Full Text(HTML)] () PDF (2694KB) ( 961 )   The thermodynamics of glycerol hydrogenolysis to produce 1,2-propanediol (1,2-PDO) and 1,3-propanediol (1,3-PDO) over Ru/ZrO2, Rh/ZrO2, ReOx-Rh/ZrO2, and ReOx-Ir/ZrO2 were studied using density functional theory calculations, with a special focus on the mechanism controlling the activity and selectivity of the reactions. It is found that the decomposition of glycerol on Ru/ZrO2 and Rh/ZrO2 proceeds through a dehydration-hydrogenation mechanism. The formation of 1,2-PDO is thermodynamically favored, and the activity of the Ru-based catalyst is higher than that of the Rh-based one. In contrast, a direct hydrogenolysis mechanism is proposed for the Re-modified Rh and Ir catalysts, in which a dissociated H atom on the Rh(Ir) metal surface attacks the C-O bond neighboring the alkoxide species on the ReOx cluster. In the presence of ReOx-Rh/ZrO2, the modified catalyst favors the production of 1,2-PDO, and 1,3-PDO production becomes competitive. However, the ReOx-Ir/ZrO2 catalyst significantly improves 1,3-PDO selectivity. The direct hydrogenolysis pathway, as opposed to the indirect hydrogenolysis mechanism for monometallic catalysts, may be the key to the high 1,3-PDO selectivity on the modified catalysts, where the hydroxylated Re group facilitates the formation of terminal alkoxide species rather than secondary alkoxides. Steric effects are important in preferential terminal alkoxide formation on the ReOx-Ir/ZrO2 catalysts because of the growth of large Ir-Re clusters, resulting in high selectivity for 1,3-PDO.

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Suzuki-Miyaura cross-coupling reaction catalyzed by a highly stable Pd(P-Phos)Cl2 complex at room temperature under air Yicen Ge, Yujing Cheng, Haiyan Fu, Xueli Zheng, Ruixiang Li, Hua Chen, Xianjun Li 2013, 34 (9):  1667-1673.  DOI: 10.1016/S1872-2067(12)60620-2 Abstract ( 501 )   [Full Text(HTML)] () PDF (501KB) ( 718 )   A new Pd(P-Phos)Cl2 complex was synthesized and characterized by 1H NMR, 13C NMR, 31P NMR, and X-ray single crystal structure determination. The complex proved to be a highly stable and efficient catalyst for substrates with a wide range of functional groups in Suzuki-Miyaura cross-coupling reactions under air at room temperature. Low catalyst loadings were employed and turnover number of up to 49000 was obtained.

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Preparation of solid acid catalyst from rice husk char and its catalytic performance in esterification Ming Li, Dengyu Chen, Xifeng Zhu 2013, 34 (9):  1674-1682.  DOI: 10.1016/S1872-2067(12)60634-2 Abstract ( 651 )   [Full Text(HTML)] () PDF (516KB) ( 968 )   A sulfonated carbon-based solid acid catalyst was prepared by sulfonating rice husk char with concentrated sulfuric acid. The as-prepared catalyst was characterized using X-ray diffraction, X-ray photoelectron spectroscopy, ultimate analysis, specific surface area analysis, and thermogravimetry-mass spectrometry. The effects of the sulfonation temperature and time on the catalytic performance were investigated using the esterification of oleic acid and methanol as the probe reaction. The effects of the reaction conditions on the esterification catalyzed by sulfonated rice husk char were also studied. The stability of the catalyst was examined. The results showed that 90℃ and 0.25 h were suitable sulfonation temperature and time, respectively. The catalyst prepared under these conditions had an amorphous carbon structure with a sulfonic group concentration of 0.7 mmol/g. It exhibited high catalytic performance. The conversion of oleic acid was 98.7% under the optimal reaction conditions with a catalyst amount of 5%, a methanol to oleic acid molar ratio of 4:1, and a reaction temperature and time of 110℃ and 2 h, respectively. The esterification conversion still reached 96.0% after seven cycles of successive reuse, which indicated that the catalyst stability was excellent.

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Au/γ-MnO2 catalyst for solvent-free toluene oxidation with oxygen Feng Jiang, Xiaowen Zhu, Baosong Fu, Jinjin Huang, Guomin Xiao 2013, 34 (9):  1683-1689.  DOI: 10.1016/S1872-2067(12)60633-0 Abstract ( 384 )   [Full Text(HTML)] () PDF (898KB) ( 1378 )   α-, δ-, and γ-MnO2 were synthesized by a redox method and Au/γ-MnO2 catalysts with different Au loadings (0.5%-3.0%) were synthesized by an in situ reduction method. The supports and catalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy (TEM), and N2 adsorption. TEM images showed that the Au particles were about 10 nm. The catalysts were used in solvent-free toluene oxidation with oxygen. The results showed that toluene conversion increased with increasing Au loading, which was ascribed to the increasing amount of Au particles and also the smaller Au particles. The Au loading gave a uniquely high selectivity to benzaldehyde. The Au/γ-MnO2 catalysts exhibited good reusability in liquid phase toluene oxidation.

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Ionic-liquid-catalyzed green synthesis of coumarin derivatives under solvent-free conditions Hamid Reza Shaterian, Morteza Aghakhanizadeh 2013, 34 (9):  1690-1696.  DOI: 10.1016/S1872-2067(12)60654-8 Abstract ( 481 )   [Full Text(HTML)] () PDF (326KB) ( 1113 )   Brönsted acidic ionic liquids, namely 2-pyrrolidonium hydrogen sulfate, N-methyl-2-pyrrolidonium hydrogen sulfate, N-methyl-2-pyrrolidonium dihydrogen phosphate, (4-sulfobutyl)tris(4-sulfophenyl)phosphonium hydrogen sulfate, and triphenyl(propyl-3-sulfonyl)phosphonium toluenesulfonate, catalyzed efficient Pechmann condensation of phloroglucinol with β-keto ethyl/ methyl esters. 5,7-Dihydroxy-4-methylcoumarin and 5,7-dihydroxy-4-phenylcoumarin were prepared in good to excellent yields under mild, ambient, and solvent-free conditions. Pyrano[2,3-h] coumarins were then prepared by one-pot three-component reactions of 5,7-dihydroxy-4-subsituted coumarin, malononitrile, and aldehydes in the presence of catalytic amounts of Brönsted basic ionic liquids, namely 2-hydroxyethylammonium formate, 3-hydroxypropanaminium acetate, 1-butyl-3-methylimidazolium hydroxide, pyrrolidinium formate, and pyrrolidinium acetate, under thermal solvent-free conditions. The catalysts are environmentally benign and can be easily prepared, stored, and recovered without significant loss of activity.

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CoFe2O4 nanoparticles：An efficient heterogeneous magnetically separable catalyst for “click” synthesis of arylidene barbituric acid derivatives at room temperature Jaspreet Kaur Rajput, Gagandeep Kaur 2013, 34 (9):  1697-1704.  DOI: 10.1016/S1872-2067(12)60646-9 Abstract ( 405 )   [Full Text(HTML)] () PDF (787KB) ( 986 )   A coprecipitation method was used to synthesize superparamagnetic CoFe2O4 nanoparticles without using any capping agents/surfactants. The prepared nanoparticles were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, a vibrating sample magnetometer (VSM), N2 adsorption and thermogravimetric/differential thermal analysis/differential thermal gravimetry techniques. The synthesized spinel CoFe2O4 nanoparticles had an average size of 2-8 nm with a high surface area (140.9 m2/g). The field-dependent magnetization, demonstrated by VSM and saturation magnetization, was found to be 1.77 emu/g. An efficient method was used for the synthesis of arylidene barbituric acid derivatives using CoFe2O4 magnetic nanoparticles as a magnetically separable and reusable catalyst in aqueous ethanol. The attractive features of this synthetic protocol were very short reaction time, high yields, high turnover frequency, simple work-up procedure, economy, a clean reaction methodology, and chemoselectivity, as well as provision of an ecofriendly and green synthesis.

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First-principles study of water activation on Cu-ZnO catalysts Kun Yao, Sha-Sha Wang, Xiang-Kui Gu, Hai-Yan Su, Wei-Xue Li 2013, 34 (9):  1705-1711.  DOI: 10.1016/S1872-2067(12)60642-1 Abstract ( 450 )   [Full Text(HTML)] () PDF (584KB) ( 719 )   Although many water-related catalytic reactions on Cu-ZnO catalysts, such as methanol steam reforming and water gas shift, have been extensively investigated, little is known about water dissociation on Cu-ZnO catalysts. To reveal the active center for water dissociation on Cu-ZnO catalysts, we performed density functional theory calculations on various domains of Cu-ZnO catalysts, including Cu surfaces, supported ZnO films, and Cu-ZnO interfaces. It is found that water dissociation is hindered by a relatively large energy barrier on both the planar and the stepped Cu surfaces. On supported ZnO films, the barrier of water dissociation is significantly lowered compared with the Cu surfaces and the reaction is essentially thermo-neutral, thus the dissociation reaction will easily reach a state of dynamic equilibrium and dissociative and molecular water can coexist on the film. At the Cu-ZnO interface, water dissociation is exothermic and proceeds essentially without an energy barrier. The enhanced activity of the Cu-ZnO interface is due to the strong adsorption of both the H atom and hydroxyl group, and the step-like structure at the interface. The low energy barrier of hydroxyl diffusion and water-assisted hydrogen diffusion on ZnO films allows water dissociation to occur continuously at the interface. This work highlights the unique role of the Cu-ZnO interface in water dissociation on Cu-ZnO catalysts.

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Methanol electro-oxidation on a porous nanostructured Ni/Pd-Ni electrode in alkaline media Mir Ghasem Hosseini, Mehdi Abdolmaleki, Sajjad Ashrafpoor 2013, 34 (9):  1712-1719.  DOI: 10.1016/S1872-2067(12)60643-3 Abstract ( 472 )   [Full Text(HTML)] () PDF (848KB) ( 816 )   A nanostructured Ni/Pd-Ni catalyst with high activity for methanol oxidation in alkaline solution was prepared by electrodeposition followed by galvanic replacement, that is, electrodeposition of Ni-Zn on a Ni coating with subsequent replacement of the Zn by Pd at the open circuit potential in a Pd-containing alkaline solution. The surface morphology and composition of the coatings were examined by energy dispersive X-ray spectroscopy and scanning electron microscopy. The Ni/Pd-Ni coatings were porous and were composed of discrete Pd nanoparticles of about 58 nm. The electrocatalytic activity of the Ni/Pd-Ni electrodes for the oxidation of methanol was examined by cyclic voltammetry and electrochemical impedance spectroscopy. The onset potentials for methanol oxidation on Ni/Pd-Ni were 0.077 V and 0.884 V, which were lower than those for flat Pd and smooth Ni electrodes, respectively. The anodic peak current densities of these electrodes were 4.33 and 8.34 times higher than those of flat Pd (58.4 mA/cm2 vs 13.47 mA/cm2) and smooth Ni (58.4 mA/cm2 vs 7 mA/cm2). The nanostructured Ni/Pd-Ni electrode is a promising catalyst for methanol oxidation in alkaline media for fuel cell application.

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Bifunctional palladium composite membrane for hydrogen separation and catalytic CO methanation Xiaojuan Hu, Wenjun Yan, Weihua Ding, Jian Yu, Yan Huang 2013, 34 (9):  1720-1729.  DOI: 10.1016/S1872-2067(12)60636-6 Abstract ( 434 )   [Full Text(HTML)] () PDF (898KB) ( 694 )   NiO was introduced into the porous Al2O3 substrate by impregnation, and the resulting NiO/Al2O3 was coated with the lead of a 2B pencil to modify its surface. A palladium layer with a thickness of 5 μm was deposited by electroless plating on the Pencil/NiO/Al2O3 substrate, and a Pd/Pencil/Ni/ Al2O3 membrane was obtained after reduction with hydrogen. For reference, a Ni-free Pd/Pencil/ Al2O3 membrane was also fabricated. The surface and cross-sectional morphologies of the membranes were studied by scanning electron microscopy and metallographic microscopy. The hydrogen permeation kinetics was investigated by single gas tests, and the hydrogen separation performances of the Pd/Pencil/Al2O3 and Pd/Pencil/NiO/Al2O3 membranes were tested with a hydrogen feed composed of H2 77.8%, CO 5.2%, CO2 13.5%, and CH4 3.5%. The Ni-free Pd/Pencil/Al2O3 membrane only shows function of hydrogen separation, while the Pd/Pencil/Ni/Al2O3 is also catalytically effective for methanation of CO and CO2 in hydrogen, forming a bifunctional palladium membrane concept. Since the amount of CO and CO2 in the hydrogen after membrane separation is very low, the consumption of hydrogen by the methanation reactions is negligible. The bifunctional membrane is promising for proton exchange membrane fuel cells because the catalytic methanation treatment solves the CO poisoning problem of the fuel cell electrodes and consequently allows the palladium membrane to tolerate more membrane defects and to achieve longer life.

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{[K.18-Crown-6]Br3}n：A tribromide catalyst for the catalytic protection of amines and alcohols Gholamabbas Chehardoli, Mohammad Ali Zolfigol, Fateme Derakhshanpanah 2013, 34 (9):  1730-1733.  DOI: 10.1016/S1872-2067(12)60644-5 Abstract ( 372 )   [Full Text(HTML)] () PDF (381KB) ( 589 )   {[K.18-Crown-6]Br3}n, a unique tribromide-type catalyst, was utilized for the N-boc protection of amines and trimethylsilylation (TMS) and tetrahydropyranylation (THP) of alcohols. The method is general for the preparation of N-boc derivatives of aliphatic (acyclic and cyclic) and aromatic, and primary and secondary amines and also various TMS-ethers and THP-ethers. The simple separation of the catalyst from the product is one of the many advantages of this method.

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Synthesis of dimethyl carbonate over starch-based carbon-supported Cu nanoparticles catalysts Jun Ren, Changjiang Guo, Leilei Yang, Zhong Li 2013, 34 (9):  1734-1744.  DOI: 10.1016/S1872-2067(12)60640-8 Abstract ( 419 )   [Full Text(HTML)] () PDF (773KB) ( 704 )   Carbon-supported Cu (Cu/C) catalyst was prepared from Cu(NO3)2 and starch, by the sol-gel method, subsequent high temperature carbonization and KOH activation. Catalyst samples were characterized by scanning and transmission electron microscopies, X-ray diffraction, thermogravimetric analysis, N2 adsorption-desorption and CO temperature-programmed desorption. Their catalytic performance in the oxidative carbonylation of methanol to dimethyl carbonate (DMC) in a fixed-bed reactor was investigated. The activation temperature and KOH content greatly influenced the catalyst microstructure and catalytic performance. The Cu/C catalyst prepared at activation temperature of 850℃ and KOH/C mass ratio of 1 exhibited the best catalytic activity. Its specific surface area and mean Cu particle size were 1690 m2/g and 30.4 nm, respectively. The space time yield was 235.7 mg·g-1·h-1, and the methanol conversion and selectivity for DMC were 1.6% and 76.5%, respectively.

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Effects of the oxidation extent of the SiC surface on the performance of Ni/SiC methanation catalysts Guoquan Zhang, Jiaxi Peng, Tianjun Sun, Shudong Wang 2013, 34 (9):  1745-1755.  DOI: 10.1016/S1872-2067(12)60639-1 Abstract ( 352 )   [Full Text(HTML)] () PDF (612KB) ( 756 )   Ni/SiC methanation catalysts were prepared by an incipient wetness impregnation method. Effects of the oxidation extent of the SiC surface on low-temperature activity and high-temperature stability of the catalysts were investigated. Samples were characterized by thermogravimetry and differential scanning calorimetry, N2 adsorption-desorption, Fourier transform infrared spectra, temperature-programmed desorption of NH3, X-ray diffraction, temperature-programmed reduction of H2 and H2 chemisorption. The surface area and nickel dispersion of the catalysts decreased with increasing oxidation temperature of the SiC supports, while both reducibility and stability of the catalysts increased. The Ni/SiC catalyst with the unoxidized SiC support showed the poorest high-temperature stability probably because of the weak anchorage of Ni particles to the support. The Ni/SiC samples prepared on the SiC supports oxidized at 500 and 700℃ had better low-temperature activity and high-temperature stability, which was because Ni particles were well dispersed on and strongly anchored to these properly oxidized supports. The Ni/SiC catalyst with the SiC support oxidized at 900℃ showed the worst low-temperature activity because of the larger Ni particles caused by the less active oxide layer due to the overoxidation of the support.

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Novel catalytic and effluent decolorization functionalities of sol-gel immobilized Pleurotus ostreatus IBL-02 manganese peroxidase produced from bio-processing of wheat straw Muhammad Asgher, Bazgha Aslam, Hafiz Muhammad Nasir Iqbal 2013, 34 (9):  1756-1761.  DOI: 10.1016/S1872-2067(12)60647-0 Abstract ( 296 )   [Full Text(HTML)] () PDF (303KB) ( 729 )   Solid state bio-processing of wheat straw was carried out through an indigenous fungal strain Pleurotus ostreatus IBL-02 under pre-optimized fermentation conditions. The maximum activity, 692±12 U/mL, of the industrially important manganese peroxidase (MnP) enzyme was recorded after five days of still culture incubation. The crude MnP was 2.1-fold purified with a specific activity of 860 U/mg after purification on a Sephadex-G-100 gel column. On native and SDS-PAGE electrophoresis gels, the purified MnP fraction was a single homogenous band of 45 kDa. An active fraction of MnP was immobilized using hydrophobic sol-gel entrapment comprising tetramethoxysilane (T) and propyltrimethoxysilane (P) at different T:P molar ratios. Characterization revealed that after 24 h incubation at varying pH and temperatures, the MnP fraction immobilized at a T:P ratio of 1:2 in the sol-gel retained 82% and 75% of its original activity at pH 4 and 70 oC, respectively. The optimally active fraction at a 1:2 T:P ratio was tested against MnSO4 as a substrate to determine the kinetic catalytic constants KM and Vmax. To explore the industrial applicability of P. ostreatus IBL-02 MnP, both the free and immobilized MnP were used for the decolorization of four different textile industrial effluents. A maximum of 100% decolorization was achieved for the different textile effluents within the shortest time period. A lower KM, higher Vmax, hyper-activation, and enhanced acidic and thermal resistance up to 70℃ were the novel catalytic features of the sol-gel immobilized MnP, suggesting that it may be a potential candidate for biotechnological applications particularly for textile bioremediation purposes.

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Low temperature CO oxidation over mesoporous CuFe2O4 nanopowders synthesized by a novel sol-gel method Ehsan Amini, Mehran Rezaei, Mohammad Sadeghinia 2013, 34 (9):  1762-1767.  DOI: 10.1016/S1872-2067(12)60653-6 Abstract ( 477 )   [Full Text(HTML)] () PDF (684KB) ( 821 )   Mesoporous CuFe2O4 solid solution nanopowders with high specific surface areas were synthesized by a novel, very simple and inexpensive sol-gel route using propylene oxide as gelation agent, and used as the catalyst in low temperature CO oxidation. The samples were characterized by X-ray diffraction, N2 adsorption-desorption, thermogravimetric/differential thermal analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and temperature-programmed reduction. The results revealed that the samples have a nanocrystalline structure with crystals in the range of 10 to 25 nm, and that all the catalysts have mesoporous pores. The addition of Cu into iron oxide affected its structural and catalytic properties. The sample containing 15 mol% Cu showed the highest specific surface area and catalytic activity, and showed high catalytic stability in low temperature CO oxidation.

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Simultaneous detection of hydroxylamine and phenol using p-aminophenol-modified carbon nanotube paste electrode Ali A. Ensafi, E. Heydari-Bafrooei, B. Rezaei 2013, 34 (9):  1768-1775.  DOI: 10.1016/S1872-2067(12)60652-4 Abstract ( 412 )   [Full Text(HTML)] () PDF (991KB) ( 728 )   A carbon paste electrode that was chemically modified with multiwall carbon nanotubes and p-aminophenol was used as a selective electrochemical sensor for the simultaneous detection of hydroxylamine (HX) and phenol. Cyclic voltammetry, double potential-step chronoamperometry, square wave voltammetry (SWV), and electrochemical impedance spectroscopy were used to investigate the use of p-aminophenol in the carbon nanotubes paste matrixes as a mediator for the electrocatalytic oxidation of HX and phenol in aqueous solution. The coefficient of electron transfer and catalytic reaction rate constant were determined using the electrochemical methods. Under optimized conditions, the electrocatalytic oxidation current peaks for HX and phenol increased linearly with concentration in the range of 0.5-180.0 and 10.0-650.0 μmol/L for HX and phenol, respectively. The detection limits for HX and phenol were 0.15 and 7.1 μmol/L, respectively. The anodic potential peaks of HX and phenol were separated by 0.65 V in SWV. Because of good selectivity and sensitivity, the present method provides a simple method for the selective detection of HX and phenol in practical samples such as water samples.

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Immobilized 2,2,6,6-tetramethyl-piperidinyl-1-oxy catalyst on polymer microspheres and its catalytic oxidation of benzyl alcohol with molecular oxygen Yiling Yu, Baojiao Gao, Yanfei Li 2013, 34 (9):  1776-1786.  DOI: 10.1016/S1872-2067(12)60651-2 Abstract ( 453 )   [Full Text(HTML)] () PDF (780KB) ( 718 )   Crosslinked polymer (glycidyl methacrylate) microspheres (CPGMA) were prepared with glycidyl methacrylate as monomer and ethylene dimethacrylate as crosslinker by suspension polymerization. The ring opening reaction between the epoxy groups on the CPGMA microspheres and 4-hydroxy-2,2,6,6-tetramethyl-piperidinyl-1-oxy (4-OH-TEMPO) was carried out to immobilize TEMPO on the polymer microspheres. TEMPO-immobilized microspheres (TEMPO/CPGMA) were obtained and were characterized by several methods. The effects of the main factors in the immobilization were examined so that the reaction conditions were optimized. On this basis, a co-catalyst system was constituted with TEMPO/CPGMA and CuCl and was used in the oxidation reaction of benzyl alcohol by molecular oxygen. The catalytic activity of the co-catalyst system and the effects of the main factors were examined. The experimental results showed that the ring opening reaction of the epoxy group allowed the immobilization of TEMPO to be smoothly realized on the CPGMA polymer microspheres, on which there were many epoxy groups. The ring opening reaction of the epoxy group is a nucleophilic substitution reaction with the SN2 reaction mechanism, and N,N'-dimethyl formamide with a strong polarity is an appropriate solvent and a suitable temperature is 85℃. The co-catalyst system consisting of the heterogeneous catalyst TEMPO/CPGMA and CuCl efficiently catalyzed the oxidation reaction of benzyl alcohol by molecular oxygen. Under mild conditions, benzyl alcohol was transformed to benzaldehyde with 100% selectivity and a yield of 90%. The suitable molar ratio of the main catalyst TEMPO/CPGMA to the co-catalyst CuCl is 1:1.2 and the suitable amount of TEMPO/CPGMA is 0.90 g. The TEMPO/CPGMA catalyst has excellent recyclability.

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In situ generated acylimidazolium acetate as an efficient catalyst and acylating agent for the acetylation of alcohols, phenols, and amines at ambient temperature Najmeh Nowrouzi, Seyedeh Zahra Alizadeh 2013, 34 (9):  1787-1790.  DOI: 10.1016/S1872-2067(12)60660-3 Abstract ( 305 )   [Full Text(HTML)] () PDF (270KB) ( 590 )   Acylimidazolium acetate was readily prepared in situ from the reaction of imidazole with acetic anhydride and subsequently acted as a catalyst and acylating agent for the efficient acetylation of alcohols, phenols, and amines at ambient temperature.

Editorial

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Impact Factor of Chinese Journal of Catalysis increases from 1.171 to 1.304 — congratulations and thanks to the authors of our most cited articles 2013, 34 (9):  1791-1795.  Abstract ( 199 )   [Full Text(HTML)] () PDF (336KB) ( 454 )   According to the Thomson Reuter report on 20 June 2013, the 2012 Impact Factor of Chinese Journal of Catalysis has improved from 1.171 to 1.304.