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Chinese Journal of Catalysis
2012, Vol. 33, No. 11
Online: 16 November 2012


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Anatase TiO₂ crystals with highly reactive {110} and {001} faces can be controllably synthesized by using information from quantum chemical calculations, as described by Wu and coworkers on pages 1743–1753. Anatase TiO₂ single crystals with exposed {110} faces have higher photocatalytic activities than P25 and anatase TiO₂ crystals without {110} faces.

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Table of Contents for Vol. 33 No. 11 2012, 33 (11):  0-0.  Abstract ( 1110 )   PDF (1544KB) ( 816 )

Research papers

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Controllable Synthesis and Photocatalytic Activity of Anatase TiO2 Single Crys-tals with Exposed {110} Facets WU Qian, WU Zhi-Jiao, LI Yong-Liang, GAO Hong-Tao, PU Ling-Yu, ZHANG Tian-Hui, DU Li-Xia 2012, 33 (11):  1743-1753.  DOI: 10.1016/S1872-2067(11)60448-8 Abstract ( 2419 )   [Full Text(HTML)] () PDF (1082KB) ( 1806 )   Anatase TiO2 single crystals with a high percentage of the high surface energy {110} facets have been successfully synthesized in a simple and economical way using a modified hydrothermal technique in the presence of hydrogen peroxide and hydrofluoric acid. The morphology and structure of the TiO2 single crystals were characterized by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The photocatalytic activity of the TiO2 crystals for the degradation of methylene blue dye was investigated by ultraviolet light irradiation. The effects of the amounts of HF and H2O2 on the morphology of TiO2 have been studied. The reaction time and temperature have also been investigated. In the TiO2 single crystals, the {001} and {110} facets are present at the same time. The results indicated that a high yield of single crystals with exposed {110} and {110} facets could be obtained by adjusting the reaction time, reaction temperature, and amounts of HF and H2O2. The anatase TiO2 single crystals with exposed {110} facets showed higher photocatalytic activities than those without.

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Activities of Key Enzymes in the Biosynthesis of Poly-3-Hydroxybutyrate by Methylosinus trichosporium IMV3011 SONG Hao, ZHANG Ying-Xin, KONG Wei-Bao, XIA Chun-Gu 2012, 33 (11):  1754-1761.  DOI: 10.1016/S1872-2067(11)60443-9 Abstract ( 2038 )   [Full Text(HTML)] () PDF (515KB) ( 688 )   The activities of the key enzymes involved in the intracellular poly-3-hydroxybutyrate (PHB) synthesis of Methylosinus trichosporium IMV3011 were studied under various cultivation conditions. The enzymes were methane monooxygenase (MMO), β-ketothiolase, acetoacetyl-CoA reductase, PHB synthetase, and PHB depolymerase. Each enzyme had a unique catalytic mechanism. MMO activity decreased continuously with PHB production, but PHB at a high concentration was beneficial for maintaining MMO activity because more NADH was released by PHB depolymerization. The important reaction for entering the PHB cycle was catalyzed by β-ketothiolase. The monomer of β-hydroxybutyrate was synthesized by the catalysis of β-ketothiolase and acetoacetyl-CoA reductase. PHB synthetase played an important role in the PHB synthesis routes. The activity of PHB synthetase increased with PHB production. The changes of enzyme activities involved in PHB synthetase and PHB depolymerase occurred together, which indicated that the polymerization and depolymerization of intracellular PHB occurred simultaneously. The molecular weight of PHB was determined mainly by the combined actions of PHB synthetase and PHB depolymerase. Some important intermediates in the tricarboxylic acid cycle were helpful for PHB production because they increased related enzyme activities in the PHB cycle.

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Effect of Zirconium Precursor on Performance of Pd/Ce0.45Zr0.45La0.1O1.95 Three-Way Catalyst CHEN Shan-Hu, YAO Yan-Ling, LAN Li, CAO Yi, YAN Chao-Yang, GONG Mao-Chu, CHEN Yao-Qiang 2012, 33 (11):  1762-1771.  DOI: 10.1016/S1872-2067(11)60445-2 Abstract ( 1944 )   [Full Text(HTML)] () PDF (557KB) ( 659 )   Three types of Ce0.45Zr0.45La0.1O1.95 mixed oxides were prepared by H2O2-assisted precipitation using ZrOCO3, ZrO(NO3)2, and Zr(NO3)4 as precursors. The Pd/Ce0.45Zr0.45La0.1O1.95 three-way catalysts were prepared by the wet impregnation and characterized by the X-ray diffraction (XRD), Raman spectroscopy, nitrogen adsorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), and oxygen storage capacity. XRD and Raman spectroscopy results showed that the use of ZrOCO3 or ZrO(NO3)2 gave a CeO2-ZrO2 mixed oxide with a cubic phase of high thermal stability, while an extra t″-phase was observed in the aged Pd/Ce0.45Zr0.45La0.1O1.95 catalyst prepared using Zr(NO3)4. The activities of the three catalysts were evaluated using simulated exhaust gas under working conditions. The Pd/Ce0.45Zr0.45La0.1O1.95 catalyst prepared using ZrOCO3 as precursor gave the best activities for C3H8, CO, and NO conversion. The use of ZrOCO3 as precursor was better suited for the formation of Ce3+ and more favorable for the homogeneous insertion of Zr4+ and La3+ into the CeO2 lattice, which resulted in better thermal stability and enhanced redox properties of the Pd/Ce0.45Zr0.45La0.1O1.95 catalyst.

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Transesterification of Glycerol with Dimethyl Carbonate to Glycerol Carbonate over Na-Based Zeolites PAN Sai-Yong, ZHENG Li-Ping, NIE Ren-Feng, XIA Shui-Xin, CHEN Ping, HOU Zhao-Yin 2012, 33 (11):  1772-1777.  DOI: 10.1016/S1872-2067(11)60450-6 Abstract ( 2320 )   [Full Text(HTML)] () PDF (406KB) ( 942 )   Glycerol carbonate (GC) was synthesized via transesterification of glycerol with dimethyl carbonate under mild conditions over a series of base zeolites. It was found that the NaY zeolite exhibited a higher selectivity for GC (100%) than heterogeneous bases (such as CaO and SrO) or homogeneous catalysts (such as NaOH and K2CO3). Further experiments over different base zeolites disclosed that this transesterification reaction depended strongly on catalyst structure. Base zeolites with small pore diameter such as 3A, 4A, and NaZSM-5 were inactive, while NaY and Naβ with larger pore diameter exhibited excellent GC yields under mild conditions.

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An Au-Cu Bimetal Catalyst Supported on Mesoporous TiO2 with Stable Catalytic Performance in CO Oxidation LI Li-Cheng, WANG Chang-Song, MA Xuan-Xuan, YANG Zhu-Hong, LU Xiao-Hua 2012, 33 (11):  1778-1782.  DOI: 10.1016/S1872-2067(11)60471-3 Abstract ( 2078 )   [Full Text(HTML)] () PDF (638KB) ( 886 )   An Au-Cu bimetal catalyst was prepared by deposition-precipitation (urea) of gold and copper species on mesoporous TiO2 and activation with H2. The sample was characterized by N2 adsorption/desorption, X-ray diffraction, ultraviolet-visible spectroscopy, and high-resolution transmission electron microscopy. The results showed that the Au and Cu species formed an Au-Cu alloy and were well dispersed on the mesoporous TiO2. According to CO oxidation test results, it was found that the catalytic activity of gold was enhanced by copper. The Au-Cu bimetal catalyst supported on mesoporous TiO2 showed better catalytic stability in CO oxidation than the Au catalyst supported on mesoporous TiO2 and the nonporous TiO2-supported catalysts. This may be related to the effects of both Au-Cu alloying and the mesostructure of TiO2.

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A Carbon Nanotube Modified Electrode for Determination of Caffeine by Differential Pulse Voltammetry Biuck HABIBI, Mehri ABAZARI, Mohammad Hossien POURNAGHI-AZAR 2012, 33 (11):  1783-1790.  DOI: 10.1016/S1872-2067(11)60438-5 Abstract ( 2252 )   [Full Text(HTML)] () PDF (548KB) ( 1264 )   A simple and sensitive electrochemical detection of caffeine (CAF) using a single-walled carbon nanotubes on carbon-ceramic electrode (SWCNT/CCE) is reported. CAF was oxidized at the surface of the modified electrode to produce an anodic peak at 1.38 V versus the saturated calomel electrode in 0.01 mol/L, pH 1.7 H2SO4 solution in cyclic voltammetry. The experimental parameters, namely, type of electrolyte, pH value, and amount of SWCNTs casted, were optimized. Using the optimum conditions, the anodic peak current in differential pulse voltammetry was linear with CAF concentration in the range of 2.5 × 10-7-1.0 × 10-4 mol/L. The detection limit was 1.2 × 10-7 mol/L (S/N = 3). The modified electrode exhibited good stability and can be easily regenerated. The relative standard deviation of the peak current obtained for a 5.0 × 10-5 mol/L CAF solution was 3.0%. The influence of some important biological compounds, namely, ascorbic acid, dopamine, and uric acid and addictive compounds like codeine, morphine, and acetaminophen on the CAF anodic peak current was examined. The method was successfully applied for the determination of CAF in some practical samples.

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Fabrication and Characterization of Perovskite-type Oxide LaFe0.9Co0.1O3 Nanoparticles and Its Performance in Aerobic Oxidation of Thiols to Disulfide Taymaz TABARI, Haman TAVAKKOLI 2012, 33 (11):  1791-1796.  DOI: 10.1016/S1872-2067(11)60442-7 Abstract ( 2293 )   [Full Text(HTML)] () PDF (466KB) ( 876 )   LaFe0.9Co0.1O3 (LFCO) perovskite nanoparticles were prepared using a sol-gel method. The physical and chemical properties of the catalyst were determined using X-ray diffraction (XRD), transmission electron microscopy, scanning electron microscopy, scanning tunneling microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, and Fourier-transform infrared spectroscopy. The catalytic activity of the sample was evaluated using aerobic oxidation of thiols to disulfides. The XRD results indicated that the LFCO had a good crystalline phase at 750 °C. The experimental data revealed that the LFCO particles were nano-sized. LFCO nanoparticles can catalyze the oxidation of various thiols, including aromatic and aliphatic thiols. The effects of reaction parameters such as temperature, solvent, and the amount of catalyst on the oxidation of 4-chlorothiophenol were investigated. In comparison with reactions using the corresponding neat complexes, i.e., Co(NO3)2·6H2O and Fe(NO3)3·9H2O, higher yields were obtained in the oxidation reaction catalyzed by LFCO nanoparticles.

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A Rapid and Green Method for Solvent-Free Synthesis of 1,8-Dioxodecahydroacridines Using Tetrabutylammonium Hexatungstate as a Reusable Heterogeneous Catalyst Abolghasem DAVOODNIA, Atefeh ZARE-BIDAKI, Hossein BEHMADI 2012, 33 (11):  1797-1801.  DOI: 10.1016/S1872-2067(11)60449-X Abstract ( 1862 )   [Full Text(HTML)] () PDF (287KB) ( 1044 )   Tetrabutylammonium hexatungstate, [TBA]2[W6O19], has been used as an efficient, inexpensive, and recyclable green catalyst for the one-pot three-component synthesis of 1,8-dioxodecahydroacridines by the reaction of dimedone with aromatic or aliphatic aldehydes in the presence of a nitrogen source (ammonium acetate or aromatic amines) under neat conditions. There are several advantages to the current process over the standard procedures available in the literature, including shorter reaction times (7–14 min), higher yields, facile work-up, and minimal environmental impact. Furthermore, the catalyst can be conveniently recovered and reused.

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Heterogenization of Indium for the Friedel-Craft Benzoylation of Toluene Farook ADAM, Kei Lin SEK 2012, 33 (11):  1802-1808.  DOI: 10.1016/S1872-2067(11)60453-1 Abstract ( 1707 )   [Full Text(HTML)] () PDF (760KB) ( 635 )   Indium incorporated silica samples with different indium contents were synthesized using a template free sol-gel method. The silica used was extracted from rice husk (RH) and the resulting catalyst was labeled as RH-xIn (x = 5%, 10%, 15%, and 20%). From the N2 adsorption analysis the presence of type IV isotherm in RH-blank and RH-xIn indicated the mesoporous nature of the catalysts. In the XRD pattern, a broad band at ca. 2θ = 25° was observed for all the catalysts which showed them to be amorphous. TEM micrographs revealed that the material is composed of nanoparticles. Friedel-Craft benzoylation of toluene was carried out using the RH-xIn catalyst. The optimum conditions for the benzoylation of toluene were determined and at 373 K, 100% conversion and 89% selectivity for the para-product (i.e. 4-methylbenzophenone) were obtained.

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Electrocatalytic Oxidation of Methanol and Ethanol by Carbon Ceramic Electrode Modified with Ni/Al LDH Nanoparticles Ghasem KARIM-NEZHAD, Sara PASHAZADEH, Ali PASHAZADEH 2012, 33 (11):  1809-1816.  DOI: 10.1016/S1872-2067(11)60452-X Abstract ( 2004 )   [Full Text(HTML)] () PDF (384KB) ( 1257 )   A Ni/Al layered double hydroxide (LDH) nanoparticle modified carbon ceramic electrode (Ni/Al LDH/NMCC) was fabricated and used for the electrocatalytic oxidation of methanol and ethanol in alkaline media. Cyclic voltammetric (CV) studies showed that it gave a significantly higher activity for methanol and ethanol oxidation and can be used as an electrocatalytic anode for fuel cells. The kinetic parameters of the electron transfer coefficient (α) and number of electrons involved in the rate determining step (nα) for the oxidation of methanol and ethanol were determined using CV. The anodic currents showed a linear dependence on the concentration of methanol and ethanol.

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Electrocatalytic Oxidation of Sodium Borohydride on a Nanoporous Ni/Zn-Ni Electrode Mir Ghasem HOSSEINI, Mehdi ABDOLMALEKI, Sajjad ASHRAFPOOR 2012, 33 (11):  1817-1824.  DOI: 10.1016/S1872-2067(11)60464-6 Abstract ( 1756 )   [Full Text(HTML)] () PDF (363KB) ( 1175 )   A Ni-Zn binary metal coating was electrochemically deposited on a copper electrode that was coated with nickel (bottom layer). This was then etched in concentrated alkaline solution (30 wt% NaOH) to produce a nanoporous Ni electrocatalytic surface for borohydride electro-oxidation in alkaline solution. The bulk and surface compositions of the coating before and after alkaline leaching were determined by atomic absorption spectroscopy and energy dispersive X-ray analysis. The surface morphology was investigated by scanning electron microscopy. The characterization showed that the leached Ni/Zn-Ni coating has a nanoporous structure. Electrocatalytic activity for borohydride electro-oxidation was assessed by cyclic voltammetry and electrochemical impedance spectroscopy. The improved activity of the electrode was related to the removal of corrosion products and the formation of nanopores and cracks during alkaline leaching. Cyclic voltammetry studies confirmed that the alkaline leaching process improved the activity of the Ni/Zn-Ni coating in comparison to that of a smooth Ni deposit, and it gave an anodic peak current density that was 21 times higher.

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Nano-Fe3O4 Encapsulated-Silica Particles Bearing Sulfonic Acid Groups as a Magnetically Separable Catalyst for Highly Efficient Knoevenagel Condensation and Michael Addition Reactions Firouzeh NEMATI, Majid M. HERAVI, Raheleh SAEEDI RAD 2012, 33 (11):  1825-1831.  DOI: 10.1016/S1872-2067(11)60455-5 Abstract ( 1993 )   [Full Text(HTML)] () PDF (316KB) ( 1857 )   Sulfonic acid-functionalized silica-coated nano-Fe3O4 particles (Fe3O4@SiO2-SO3H) have been prepared as a novel heterogeneous acid using a facile process. The material was subsequently identified as an efficient catalyst for the synthesis of a variety of tetraketone derivatives via the Knoevenagel condensation and Michael addition reactions of aromatic aldehydes to dimedone, 1,3-indanedione, and 1,3-dimethyl barbituric acid. The catalyst could be readily recovered using a simple external magnet and reused several times without any significant loss in activity. The current catalytic process is both sustainable and economical because it operates under aqueous conditions, the catalyst can be recovered and reused, and the reactions themselves require only a short time and provide the products in high yield.

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Application of Amino-Functionalized SBA-15 Type Mesoporous Silica in One-Pot Synthesis of Spirooxindoles Ghodsi MOHAMMADI ZIARANI, Alireza BADIEI, Somayeh MOUSAVI, Negar LASHGARI, Afsaneh SHAHBAZI 2012, 33 (11):  1832-1839.  DOI: 10.1016/S1872-2067(11)60456-7 Abstract ( 2062 )   [Full Text(HTML)] () PDF (393KB) ( 1513 )   Amino-functionalized SBA-15 (SBA-Pr-NH2) has been used as a new basic nanocatalyst in the one-pot synthesis of spirooxindole derivatives via the three-component condensation reaction of isatins, activated methylene reagents, and dimedone in an aqueous medium. SBA-Pr-NH2 has been established as an efficient heterogeneous nanoporous solid basic catalyst (pore size of 6 nm) that can be easily handled and removed from the reaction mixture by simple filtration, and also recovered and reused without noticeable loss of reactivity.

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Silica-Bonded N-Propylpiperazine Sodium n-Propionate as Recyclable Basic Catalyst for Synthesis of 3,4-Dihydropyrano[c]chromene Derivatives and Biscoumarins Khodabakhsh NIKNAM, Abbas JAMALI 2012, 33 (11):  1840-1849.  DOI: 10.1016/S1872-2067(11)60457-9 Abstract ( 1962 )   [Full Text(HTML)] () PDF (371KB) ( 940 )   A simple and efficient procedure for the preparation of silica-bonded N-propylpiperazine sodium n-propionate (SBPPSP) by the hydrolysis of silica-bonded N-propylpiperazine methyl n-propionate (SBPPMP) in hydrochloric acid (0.5 mol/L) followed by treatment with saturated sodium bicarbonate is described. The SBPPMP was obtained by the reaction of 3-silica-bonded N-propylpiperazine and methyl acrylate in methanol. SBPPSP was used as a recyclable basic catalyst for the synthesis of 3,4-dihydropyrano[c]chromenes by the reaction of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin in aqueous ethanol (1:1 v/v) under reflux conditions. Biscoumarins were also obtained via condensation of aldehydes and 4-hydroxycoumarin in aqueous ethanol (1:1 v/v) under reflux conditions. The catalyst could be recycled several times without any additional treatment.

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Adsorption and Decomposition of N2O on Cu/t-ZrO2(101) Surfaces MAN Mei-Ling, GU Jia-Fang, LI Lu, LIN Hua-Xiang, LI Yi, CHEN Wen-Kai 2012, 33 (11):  1850-1856.  DOI: 10.3724/SP.J.1088.2012.20458 Abstract ( 1705 )   [Full Text(HTML)] () PDF (1080KB) ( 1086 )   The density functional theory and slab models have been applied to investigate the adsorption and dissociation of N2O on perfect t-ZrO2 (101) and Cu/t-ZrO2 (101) surfaces. The results indicated that N2O adsorption on the ZrO2(101) surface is physical adsorption. The first of sub-surface oxygen site is the most stable adsorption site for the Cu/ZrO2(101) surface, and when the coverage is 0.25 ML, the most stable models were obtained with adsorption energy of 155.8 kJ/mol. The adsorption of N2O on the Cu/t-ZrO2(101) surface by O-end is weak physical adsorption, and the N-end and parallel adsorption energy is 121.6 and 66.8 kJ/mol, respectively. Vibrational frequency and the Mulliken population were calculated, and the results indicated that the symmetric and antisymmetric vibrational frequencies are red-shifted and the charge transfers from Cu/t-ZrO2(101) to N2O after adsorption. The N-end and parallel dissociation process were considered and the parallel dissociation process is more feasible.

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Kinetics of Liquid Lipase NS81006-Catalyzed Alcoholysis of Oil for Biodiesel Production Lü Liang-Liang, DU Wei, LIU De-Hua 2012, 33 (11):  1857-1861.  DOI: 10.3724/SP.J.1088.2012.20638 Abstract ( 1830 )   [Full Text(HTML)] () PDF (441KB) ( 808 )   Biodiesel production catalyzed by liquid lipase has been drawing more attention for its lower cost and faster reaction rate compared to immobilized lipase. The liquid lipase NS81006-catalyzed methanolysis and ethanolysis of soybean oil for biodiesel production were studied. A kinetic model was established by taking transesterification reactions, as well as hydrolysis and esterification reactions into consideration. The corresponding values of rate constants were then obtained for all forward and reverse reactions based on the model. The results show that the transesterification reaction rates are obviously higher than the hydrolysis reaction rates either with methanol or ethanol as the acyl acceptor. Further study indicates that the rate constants of ethanolysis are smaller than that of methanoslysis, which results in the difference in reaction rate between methanolysis and ethanolysis.

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Synthesis of Zeolite A and Its Application as a High-Capacity Cadmium Ion Exchanger WANG Chun-Yan, ZHOU Ji-Ti, HE Jun-Kang, HAO Chuan-Song, PAN Yu-Zhen, MENG Chang-Gong 2012, 33 (11):  1862-1869.  DOI: 10.3724/SP.J.1088.2012.20835 Abstract ( 1979 )   [Full Text(HTML)] () PDF (592KB) ( 655 )   A facile method comprised of alkali fusion activation and hydrothermal reaction was developed to synthesize high-quality crystallized zeolite A from cost-effective low-grade bauxite. Using sodium aluminate powder as an extra aluminum source and sodium carbonate as an activator, the reactant molar ratios of SiO2/Al2O3, Na2O/SiO2, and H2O/Na2O, the hydrothermal reaction time are optimized in detail. Highly crystallized phase-pure zeolite A is successfully synthesized from low-grade bauxite under the optimized experimental conditions of 1.5 Na2O:0.5 Al2O3:1 SiO2:128 H2O after hydrothermal reaction at 90 oC for 12 h. The cadmium ion removal from aqueous solutions using the as-synthesized zeolite A powders as an adsorbent was studied. The effects of contact time, solution concentration, solution pH value, and adsorbent amount on adsorption was investigated. The adsorption equilibrium could be reached very fast within 90 min. The adsorption followed a pseudo-second-order kinetic adsorption mode well. Both Langmuir and Freundlich models could fit the experimental data well at pH = 6. The maximum adsorption capacity was estimated to be 161.3 mg/g. The optimal adsorbent dosage is about 1.00 g/L.