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Chinese Journal of Catalysis
2011, Vol. 32, No. 10
Online: 30 September 2011


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Prof. Huang and coworkers in their article on pages 1573–1576 report the enantioselective aza-Michael addition of aromatic amines to nitroolefins catalyzed by chiral phosphoric acid. The chiral phosphoric acid catalyst showed high aza-Michael addition reactivity and good stereoselectivity.

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Table of Contents for Vol.32 No. 10 2011, 32 (10):  0-0.  Abstract ( 1067 )   PDF (720KB) ( 750 )

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Research Progress in Photocatalytic Conversion of CO2 to Hydrocarbons WU Cong-Ping, ZHOU Yong, ZOU Zhi-Gang 2011, 32 (10):  1565-1572.  DOI: 10.3724/SP.J.1088.2011.10509 Abstract ( 5828 )   [Full Text(HTML)] () PDF (593KB) ( 7167 )   CO2 photoreduction as typical advanced technology has been becoming one of the most promising solutions to mitigate CO2 emissions. Firstly, emission reduction and utilization of CO2 was introduced. Then the present research status of photocatalytic conversion of CO2 was reviewed, with particular attention to our recent progress on this field. The artificial photosynthesis technology helps one partially reduce atmospheric CO2 levels and fulfill the recycle utilization of CO2. Finally, challenges and prospects for further development of this field are presented.

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Chiral Phosphoric Acid Catalyzed Enantioselective Aza-Michael Addition of Aromatic Amines to Nitroolefins YANG Lei, XIA Chun-Gu, HUANG Han-Min 2011, 32 (10):  1573-1576.  Abstract ( 2582 )   [Full Text(HTML)] () PDF (685KB) ( 808 )   Chiral phosphoric acid was found to be an effective organocatalyst in the enantioselective aza-Michael addition of aromatic amines to nitroolefins giving the corresponding β-nitroamine products in good yields (65%–95%) with moderate to good enantiomeric excesses (16%–70%). This study represents the first example of a chiral phosphoric acid catalyzed asymmetric aza-Michael addition reaction.

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Synthesis of Graphene-CdSe Composite by a Simple Hydrothermal Method and Its Photocatalytic Degradation of Organic Dyes OH Won-Chun, CHEN Mingliang, CHO Kwangyoun, KIM Cheolkyu, MENG Zeda, ZHU Lei 2011, 32 (10):  1577-1583.  DOI: 10.1016/S1872-2067(10)60264-1 Abstract ( 3240 )   [Full Text(HTML)] () PDF (608KB) ( 1924 )   A graphene-CdSe composite was synthesized by a facile hydrothermal method, and characterized by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy and UV-vis diffuse reflectance spectrophotometry. The graphene-CdSe composite efficiently catalyzed the photodegradation of methylene blue (MB), methyl orange (MO) and rhodamine B (Rh.B) in aqueous solution under UV or visible light irradiation. The graphene-CdSe composite exhibited a higher photocatalytic activity for the MB solution.

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Effects of Succinic Anhydride Modification on Laccase Stability and Phenolics Removal Efficiency XIONG Ya-Hong, GAO Jing-Zhong, ZHENG Jian-Peng, DENG Nai-Kang 2011, 32 (10):  1584-1591.  DOI: 10.1016/S1872-2067(10)60262-8 Abstract ( 3021 )   [Full Text(HTML)] () PDF (371KB) ( 968 )   Chemical modification is a useful method to change the properties of enzymes. Laccase is a phenol oxidase belonging to a multicopper protein, which catalyzes the oxidation of many phenolics. DeniLite IIS, a commercial laccase preparation from the Novozymes China Company, was purified by ammonium sulfate fractional precipitation. Succinic anhydride (SA) was used as a modifier for the chemical modification of the purified laccase. The effects of modification were characterized using the 6-trinitrobenzene sulfonic acid method, ultraviolet spectroscopy, and fluorescence spectroscopy. The pH stability, thermal stability, and the phenolics removal efficiency for the native and modified laccases were compared. The results showed that the average amino modification yield of the modified laccase was 85% and the modified laccase had a blue shifted ultraviolet peak and fluorescence emission peak as well as a decrease in the ultraviolet absorbance and an increase in the fluorescence intensity. Although chemical modification with SA did not change the optimum temperature for the catalysis of the laccase, it caused the optimum pH of the catalysts to shift from 4.5 to 5.5 and the enzymatic activity increased by 60%. Compared with the native laccase, the modified laccase exhibited remarkably higher pH stability and thermal stability and its catalysis efficiency (kcat) and substrate affinity (kcat/Km) increased by 53% and 122%, respectively. The phenolics removal efficiency (o-, m-, p-dihydroxybenzene) of the modified laccase increased by 48%, 57%, and 18%, respectively. These results indicate that the modified laccase with higher stability and higher efficiency is suitable for application in industrial production and for the treatment of phenolics-polluted water.

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Biodiesel Production from Soybean Oil Catalyzed by K2SiO3/C WANG Jian-Xun, CHEN Guang-Chong, CHEN Jin-Zhang 2011, 32 (10):  1592-1596.  DOI: 10.1016/S1872-2067(10)60265-3 Abstract ( 3689 )   [Full Text(HTML)] () PDF (664KB) ( 924 )   A solid base catalyst (K2SiO3/C) capable of microwave absorption was used for the transesterification of soybean oil under microwave radiation. The K2SiO3/C catalyst was prepared by an impregnation method that loaded K2SiO3 on carbon particles (1–3.5 mm diameter) followed by drying at 120 °C. The catalysts were characterized by X-ray diffraction, scanning electron microscopy- energy dispersive spectrometry, and the Hammett indicator method. K2SiO3 was well distributed on the support. The effects of reaction variables such as catalyst loading, molar ratio of methanol to oil, and reaction time (under microwave radiation and conventional heating) were studied. When the conventionally heated reaction was carried out at 65 °C with a methanol/oil molar ratio of 30:1 and a catalyst concentration of 24 wt%, the biodiesel conversion was 96.5% after 2.5 h reaction time. The same reaction reached equilibrium after 1.5 h under microwave radiation, and the conversion of biodiesel was 96.7%.

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Catalytic Activity of Dual Metal Cyanide Complex in Multi-component Coupling Reactions Anaswara RAVINDRAN, Rajendra SRIVASTAVA 2011, 32 (10):  1597-1603.  DOI: 10.1016/S1872-2067(10)60266-5 Abstract ( 2335 )   [Full Text(HTML)] () PDF (879KB) ( 1489 )   Several dual metal cyanide catalysts were prepared from potassium ferrocyanide, metal chloride (where metal = Zn2+, Mn2+, Ni2+, Co2+ and Fe2+), t-butanol (complexing agent) and PEG-4000 (co-complexing agent). The catalysts were characterized by elemental analysis (CHN and X-ray fluorescence), X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, Fourier-transform infrared spectroscopy, and UV-Visible spectroscopy. The dual metal cyanide catalysts were used in several acid catalyzed multi-component coupling reactions for the synthesis of pharmaceutically important organic derivatives. In all these reactions, the Fe-Fe containing dual metal cyanide catalyst was the best catalyst. The catalysts can be recycled without loss in catalytic activity. The advantage of this method is the use of mild, efficient and reusable catalysts for various reactions, which makes them candidates for commercial use.

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Effects of Selected Promoters on Ni/γ-Al2O3 Catalyst Performance in Methane Dry Reforming Ahmed S. A. AL-FATESH, Anis H. FAKEEHA, Ahmed E. ABASAEED 2011, 32 (10):  1604-1609.  DOI: 10.1016/S1872-2067(10)60267-7 Abstract ( 2679 )   [Full Text(HTML)] () PDF (831KB) ( 1331 )   The Ni catalysts supported on γ-Al2O3 were synthesized by an impregnation method. Their catalytic performance in methane dry reforming was investigated. The reforming reactions were carried out in a microreactor using a CO2:CH4 feed ratio of 1:1, a F/W = 2640 ml/(h·g), reaction temperatures between 500–850 °C, and at atmospheric pressure. The influence of Ca, Ce, and Zr promoters on catalyst stability, coke deposition, and the H2/CO ratio were also studied. Effluents were analyzed using an online gas chromatograph equipped with a thermal conductivity detector. The spent and fresh catalysts were characterized by scanning electron microscopy and thermogravimetric analysis. It was found that 3%Ni/γ-Al2O3 promoted with 0.15% Ce and 0.05% Ca gave the best performance and resulted in less coke formation. The highest CH4 and CO2 conversion activities were found to be 94.1% and 98.3% at 850 °C, respectively. Stability tests were carried out for 130 h and this provided a H2 yield of 91%. Moreover, the amount of formed carbon was negligible and did not increase to more than 1.5 wt%.

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Catalytic Modulation on the Regioselectivity of the Photosensitized Oxidation of α-Pinene with Molecular Oxygen under Sodium Lamp Irradiation YOU Kui-Yi, YIN Du-Lin, MAO Li-Qiu, LIU Ping-Le, LUO He-An 2011, 32 (10):  1610-1616.  DOI: 10.1016/S1872-2067(10)60271-9 Abstract ( 2784 )   [Full Text(HTML)] () PDF (358KB) ( 834 )   A simple and efficient photosensitized catalytic oxidation approach for α-pinene with molecular oxygen in a temperature-controlled reactor with sparged dioxygen as oxidant and an immersed high-pressure sodium lamp as a green irradiation light source was developed. The effects of various catalysts and reaction parameters on reaction performance were studied. The results indicated that 98% conversion with 84% total selectivity for verbenone and verbenol was obtained when N,N′-dimethylformamide (DMF) was used as a solvent. The product distributions were remarkably affected by the reaction media and DMF was found to especially modulate the regioselectivity of the products. Moreover, a possible photosensitized catalytic oxidation reaction mechanism in DMF is proposed and a clear acid-base synergetic catalysis effect was evident. The relationship between chemical reactivity and selectivity was modeled using density functional theory at the B3LYP/6-311+G(d) level from optimized molecular configurations.

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Preparation and Application of New P, N-Ligands for Palladium-Catalyzed C–N Bond Coupling Reaction DAI Yao, LIU He-Song, FENG Xiu-Juan, BAO Ming 2011, 32 (10):  1617-1623.  DOI: 10.3724/SP.J.1088.2011.10617 Abstract ( 2995 )   [Full Text(HTML)] () PDF (441KB) ( 1657 )   P,N-ligands (L1–L5) with cyclic secondary amine moieties linked to the benzene rings of triphenylphosphine were designed and synthesized for the palladium-catalyzed C–N bond coupling reactions. The structures of these new P,N-ligands were confirmed by 1H NMR, 13C NMR, 31P NMR, infrared, high resolution mass spectroscopy, and X-ray single crystal diffraction. The desired C–N bond coupling products were obtained in good to excellent yields (up to 95%) when the reactions of aryl bromides with secondary amines were performed under the optimized reaction conditions (Pd2(dba)3, 1 mol%; L5, 6 mol%; NaOtBu, 1.4 mmol; toluene, 2.5 ml; 100 oC).

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Preparation of Cd2Ge2O6 Nanorods by a Hydrothermal Method and Their Photocatalytic Performance in Liquid Phase CHEN Jian-Qin, HUANG Jian-Hui 2011, 32 (10):  1624-1630.  DOI: 10.3724/SP.J.1088.2011.10602 Abstract ( 2250 )   [Full Text(HTML)] () PDF (744KB) ( 814 )   Cd2Ge2O6 nanorods were successfully synthesized by a hydrothermal method using cetyltrimethylammonium bromide, cadmium acetate, and germanium dioxide as the precursors. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activity was evaluated by the decomposition of methyl orange and salicylic acid in aqueous solution. The active oxygen species in the photocatalytic process were detected by the method of chemiluminescent fluorescence. The results reveal that Cd2Ge2O6 nanorods can be prepared under weak basic conditions by the hydrothermal method. The Cd2Ge2O6 nanorods have a higher photocatalytic activity for decomposing organic pollutants in aqueous solution than the widely used commercial TiO2. In the photocatalytic process of Cd2Ge2O6, a large number of hydroxyl radicals were produced, which are the main active oxygen species of the photocatalytic system.

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Citric Acid-Assisted Hydrothermal Synthesis of Bi2WO6 Nanosheets for Highly Efficient Degradation of Methyl Orange under Visible Light Irradiation CHEN Yuan, LIU Guo-Cong, LI Zhi-You, HUANG Su-Ping, ZHOU Ke-Chao 2011, 32 (10):  1631-1638.  DOI: 10.3724/SP.J.1088.2011.10531 Abstract ( 2972 )   [Full Text(HTML)] () PDF (579KB) ( 1365 )   Bi2WO6 nanosheets with highly efficient photocatalytic activity under visible light irradiation were prepared by a hydrothermal method using Bi(NO3)3·5H2O and Na2WO3·2H2O as starting materials and citric acid as the chelating agent. The properties of the as-prepared samples were investigated by X-ray diffraction, field emission high resolution transmission electron microscopy, Raman spectroscopy, and UV-Vis diffusion reflectance spectroscopy. The photocatalytic properties of the Bi2WO6 catalyst were also investigated. The results show that Bi2WO6 nanosheets with orthorhombic structure can be obtained by adjusting the pH value of the reaction system. Compared with the Bi2WO6 catalyst prepared without citric acid, the Raman bands of the nanosheets assisted with citric acid present blue shift and show a significant red shift in the absorption band and its band gap was narrowed to 2.55 eV. The pH value of the reaction system is the main factor affecting the visible light-driven photocatalytic activity. The Bi2WO6 sample prepared at pH = 7.0 shows a higher photocatalytic activity. Over this catalyst, the 100% degradation of methyl orange solution (10 mg/L) is obtained after visible light irradiation for 15 min. In addition, after 5 recycles, there is no significant decrease in its photocatalytic activity, indicating that Bi2WO6 is a stable photocatalyst for degradation of methyl orange under visible light irradiation.

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Asymmetric Transesterification Resolution of (R,S)-α-Phenylethanol in a Non-aqueous Medium by Microbial Lipase QIN Li-Na, YU Xiao-Wei, XU Yan 2011, 32 (10):  1639-1644.  DOI: 10.3724/SP.J.1088.2011.10601 Abstract ( 2524 )   [Full Text(HTML)] () PDF (795KB) ( 965 )   By utilizing lipases that come from different microorganisms as catalyst, vinyl acetate as acyl donor, the asymmetric transesterification resolution of (R,S)-α-phenylethanol in non-aqueous media was conducted. Among the 15 enzymes investigated, lipase PS from Burkholderia cepacia showed higher activity and enantioselectivity. The effects of substrate concentration, reaction medium, enzyme dosage, reaction time, temperature, and water activity on the reaction were investigated. The results indicated that the optimal reaction conditions were as follows. The reaction was carried out with 5 mg/ml lipase PS, 0.3 mol/L (R,S)-α-phenylethanol, and 0.6 mol/L vinyl acetate in hexane. The mixture was then shaken under 35 °C and 200 r/min with the initial water activity of 0.75 for 14 h. Under the optimal conditions, the substrate conversion could reach 44.7% with 98.6% ee of (R)-phenylethyl acetate. Water activity was found to be an important factor to the product enantioselectivity and substrate conversion.

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Preparation and Hydrodeoxygenation Properties of Ni-Co-W-B Amorphous Catalyst WANG Wei-Yan, YANG Yun-Quan, LUO He-An, PENG Hui-Zuo- Zhang-Xiao-Zhe, HU Tao 2011, 32 (10):  1645-1650.  DOI: 10.3724/SP.J.1088.2011.10639 Abstract ( 2736 )   [Full Text(HTML)] () PDF (843KB) ( 847 )   Ni-Co-W-B amorphous catalysts with different Ni/Co ratios were prepared by the chemical reduction method, and their hydrodeoxygenation (HDO) activity was tested using phenol as the model compound. All the fresh catalysts showed an amorphous structure, and the electron transfer between Ni0 and B0 occurred in the Ni-Co-W-B amorphous catalysts. The thermal stability of the amorphous catalyst increased and the Ni0 content decreased with increasing Co content. The HDO of phenol on the Ni-Co-W-B amorphous catalysts proceeded through a hydrogenation-deoxygenation route, and no benzene was found in the products. When the Ni:Co atom ratio in the raw material was 2:1, the Ni-Co-W-B amorphous catalyst showed the highest HDO activity. Under the conditions of temperature 275 oC, hydrogen pressure 4.0 MPa, and reaction time 2 h, the phenol conversion and the deoxygenation rate reached 99.4% and 86.0%, respectively. The HDO activity of the Ni-Co-W-B amorphous catalysts depended on the Ni0 content, the Brönsted acidity, and the catalyst surface area.

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Preparation and Photocatalytic Performance of One-Dimensional CdS/TiO2 ZHU Bao-Lin, ZHAO Wei-Ling, ZENG Chen-Jie, CHEN Jie, HAN Qi-Wei, HUANG Wei-Ping 2011, 32 (10):  1651-1655.  DOI: 10.3724/SP.J.1088.2011.10605 Abstract ( 2547 )   [Full Text(HTML)] () PDF (596KB) ( 1200 )   By using hydrogen titanate nanotubes as support and titanium sol composed of CdCl2 and thiourea as modifying precursor, one-dimensional CdS/TiO2 catalysts with different CdS contents were prepared after calcination. The prepared materials were characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption, UV-Vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Using methyl orange solution as wastewater, the photocatalytic activity of CdS/TiO2 was investigated under UV light and simulated sunlight irradiation. The results indicate that the tubular structure of titanate nanotubes is damaged and one-dimensional TiO2 crystals form after the calcination process at high temperature. After TiO2 is modified by CdS, improved photocatalytic performance is obtained, and 3% CdS/TiO2 calcined at 400 ºC exhibits the best catalytic performance.

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Synthesis of Hierarchical TS-1 Zeolite Using Cationic Polymer as Mesoporous Template WANG Xiao-Xing, LI Gang, LIU Li-Ping, LIU Hai-鸥 2011, 32 (10):  1656-1661.  DOI: 10.3724/SP.J.1088.2011.10653 Abstract ( 2598 )   [Full Text(HTML)] () PDF (858KB) ( 1355 )   Hierarchical TS-1 zeolites were synthesized successfully by the hydrothermal method using cationic polyquaternium-7 and polyquaternium-6 as mesoporous template, respectively. The obtained samples were characterized by X-ray diffraction, UV-Visible spectroscopy, scanning electron microscopy, transmission electron microscopy, and N2 adsorption-desorption. The catalytic performance of the materials was evaluated for the oxidation of bulky molecular benzothiophene and small molecular thiophene. The results show that the addition of polyquaternium-7 has a little effect on the crystallization, the state of titanium sites, and the crystal morphology of hierarchical TS-1. However, the crystal morphology of hierarchical TS-1 changes from small cubic crystals to large rectangular crystals with increasing content of polyquaternium-6. Hierarchical TS-1 zeolites synthesized from the two kinds of polymers possess obvious mesoporous channels. Moreover, they give much higher activity in benzothiophene oxidation than TS-1, which is attributed to the presence of additional mesopores for reducing the diffusion limitation. In addition, hierarchical TS-1 zeolites also exhibit the similar oxidative activity for thiophene to TS-1 and give the removal rate of 100% for 2 h.