催化学报

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第33卷第11期目次

2012, 33 (11): 0-0.

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具有{110}面的锐钛矿 TiO₂ 单晶的可控合成与光催化性能

吴谦, 吴志娇, 李永良, 高洪涛, 朴玲钰, 张天慧, 杜利霞

2012, 33 (11): 1743-1753. DOI: 10.1016/S1872-2067(11)60448-8

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采用水热法合成了同时具有最高表面能{110}和{001}晶面的锐钛矿 TiO₂单晶, 通过 X 射线衍射、扫描电镜和激光拉曼光谱等手段对样品的形貌和结构进行了表征, 并系统考察了过氧化氢、氢氟酸和反应温度等关键因素对所得样品中{110}面比例的影响, 实现了持续提高{110}面比例的过程. 在光催化降解亚甲基蓝反应中, 具有{110}面的锐钛矿 TiO₂ 单晶的光催化活性显著高于无{110}面的单晶.

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甲基弯菌 IMV3011 生物催化合成聚 β-羟基丁酸酯途径中关键作用酶的活性

宋昊, 张颖鑫, 孔维宝, 夏春谷

2012, 33 (11): 1754-1761. DOI: 10.1016/S1872-2067(11)60443-9

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研究了甲烷单加氧酶 (MMO)、β-酮硫解酶、乙酰乙酰 CoA 还原酶、聚 β-羟基丁酸酯 (PHB) 合成酶及 PHB 降解酶在甲烷氧化细菌胞内 PHB 合成途径中的催化作用. 结果表明, MMO 的活性随着胞内 PHB 的积累而持续下降, 而胞内高含量的 PHB 有助于减缓 MMO 活性的降低. β-酮硫解酶控制着反应体系进入 PHB 循环的入口, 在它和乙酰乙酰 CoA 还原酶的共同作用下, 生成聚合单体 β-羟基丁酰, 二者活性在对数生长期达到峰值. PHB 合成酶可将胞内的短链片段聚合, 形成具有稳定高分子量的长链聚酯; 当 PHB 合成酶活性最高时, 胞内 PHB 浓度也随之达到峰值. 同时, PHB 降解酶活性随着 PHB 合成酶活性的增加而增加, 表明在 PHB 循环中, PHB 的合成和降解实际上是同时发生的. PHB 合成酶的活性基本决定了 PHB 的分子量, 但最终取决于 PHB 合成酶和 PHB 降解酶的共同作用.

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不同锆源对 Pd/Ce_0.45Zr_0.45La_0.1O_1.95 整体式三效催化剂性能的影响

陈山虎, 姚艳玲, 兰丽, 曹毅, 闫朝阳, 龚茂初, 陈耀强

2012, 33 (11): 1762-1771. DOI: 10.1016/S1872-2067(11)60445-2

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分别以 ZrOCO₃, ZrO(NO₃)₂ 和 Zr(NO₃)₄ 为锆源采用双氧水氧化-共沉淀法合成了 Ce_0.45Zr_0.45La_0.1O_1.95 储氧材料, 并用湿法浸渍法制备了 Pd/Ce_0.45Zr_0.45La_0.1O_1.95 三效催化剂, 用 X 射线衍射、拉曼光谱、N₂ 吸附、X 射线光电子能谱、氢气程序升温还原和氧脉冲等技术对该催化剂进行了表征. 结果表明, 以 ZrOCO₃ 和 ZrO(NO₃)₂ 为锆源时所制催化剂上只能检测到单一的 CeO₂-ZrO₂ 立方相, 而以 Zr(NO₃)₄ 为锆源制备的催化剂经老化后却能检测到四方相; 另外, 在模拟汽车尾气组分和工作条件下考察了整体型 Pd/Ce_0.45Zr_0.45La_0.1O_1.9 催化剂的三效活性. 结果表明, 以 ZrOCO₃ 为前驱体制备的整体式 Pd/Ce_0.45Zr_0.45La_0.1O_1.9 催化剂对 C₃H₈, CO 和 NO 具有最佳的催化活性. 认为 ZrOCO₃ 更有利于 Zr⁴⁺ 和 La³⁺进入 CeO₂ 晶格形成均一固溶体, 从而提高催化剂的高温稳定性和氧化还原性能.

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碱性分子筛作用下甘油与碳酸二甲酯反应制碳酸甘油酯

潘赛勇, 郑丽萍, 聂仁峰, 夏水鑫, 陈平, 侯昭胤

2012, 33 (11): 1772-1777. DOI: 10.1016/S1872-2067(11)60450-6

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报道了温和条件下甘油和碳酸二甲酯在一系列碱性催化剂作用下合成碳酸甘油酯的活性规律和构效关系. 结果表明, 在所选择的催化剂中, NaY 分子筛对目标反应具有较高的活性和最高的目的产物选择性; 另外, 甘油和碳酸二甲酯的反应对催化剂的孔道结构具有特殊的要求, 3A, 4A 和 NaZSM-5 等孔径较小 (< 0.6 nm) 的分子筛没有催化活性, 而孔径较大的 NaY 和 Naβ 则表现出较高的催化活性.

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一种具有 CO 催化氧化稳定性的金铜双金属/介孔氧化钛催化剂

李力成, 王昌松, 马璇璇, 杨祝红, 陆小华

2012, 33 (11): 1778-1782. DOI: 10.1016/S1872-2067(11)60471-3

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将金、铜前驱体沉积沉淀到介孔氧化钛材料上, 再经氢气活化后制备了双金属催化剂 Au-Cu/TiO₂, 并采用 N₂ 吸附/脱附、X 射线粉末衍射、紫外-可见光谱和高分辨透射电镜等对样品进行了表征. 结果显示, 金和铜形成合金相, 且良好地分散在介孔氧化钛上. CO 氧化反应结果表明, Cu 可以提高 Au 催化剂的催化性能, Au-Cu/TiO₂ 催化剂比 Au/TiO₂ 和无孔氧化钛负载的 Au 催化剂具有更好的 CO 催化氧化稳定性. 这可能与 Au, Cu 合金化和氧化钛的介孔结构有关.

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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

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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 LaFe_0.9Co_0.1O₃ 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

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LaFe_0.9Co_0.1O₃ (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

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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

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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-methylbenzonphenone) 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

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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 (n_α) 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

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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

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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

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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

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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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N₂O 在 Cu/t-ZrO₂(101) 表面的吸附与解离

满梅玲, 辜家芳, 李璐, 林华香, 李奕, 陈文凯

2012, 33 (11): 1850-1856. DOI: 10.3724/SP.J.1088.2012.20458

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运用广义梯度密度泛函理论结合周期性平板模型方法研究了 N₂O 在完整及负载 Cu 的四方相 ZrO₂(101) 表面的吸附与解离. 结果表明, N₂O 在完整 ZrO₂(101) 表面的吸附均为物理吸附, Cu 在其完整表面的次表层第一氧位为最稳定吸附位, 且覆盖度为 0.25 ML 时的吸附最为稳定, 吸附能为 155.8 kJ/mol; N₂O 分子中 O 端弱物理吸附于 Cu/ZrO₂(101) 表面, 其 N 端及平行吸附方式得到的稳定吸附能分别为 121.6 和 66.8 kJ/mol. 频率及电荷布居计算表明, 吸附后对称和反对称伸缩振动频率均发生红移, 电子由 Cu 负载底物表面转移给 N₂O 分子. 对 N₂O 分子的解离考虑了 N 端垂直吸附和平行吸附两种解离反应过程, 发现平行吸附过程的解离更易发生.

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游离脂肪酶 NS81006 催化油脂醇解制备生物柴油的酶促反应动力学

吕亮亮, 杜伟, 刘德华

2012, 33 (11): 1857-1861. DOI: 10.3724/SP.J.1088.2012.20638

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探究了游离脂肪酶 NS81006 催化油脂甲 (乙) 醇解制备生物柴油的反应历程, 并对该体系进行了酶促反应动力学研究. 结果表明, 催化过程中油脂同时存在酯交换及先水解再酯化两种反应历程. 在以甲醇或乙醇作为酰基受体的反应过程中, 酯交换反应速率明显大于水解反应速率. 进一步研究表明, 油脂甲醇解反应速率常数大于乙醇解, 揭示了以甲醇或乙醇为不同酰基受体时反应速率存在差异的主要原因在于乙醇解反应的酯交换过程较慢.

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A 型分子筛的合成及其对镉离子的吸附性能

王春燕, 周集体, 何俊慷, 郝传松, 潘玉珍, 孟长功

2012, 33 (11): 1862-1869. DOI: 10.3724/SP.J.1088.2012.20835

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以廉价的低品位铝矾土为原料, 以偏铝酸钠为补充铝源, 以碳酸钠为活化剂, 采用碱熔融-水热法合成了 A 型分子筛, 考察了水热条件对所制分子筛的影响, 发现 SiO₂/Al₂O₃, Na₂O/SiO₂ 和 H₂O/Na₂O 摩尔比及反应时间是影响产物晶型的主要因素, 其最佳合成工艺条件是: 反应物配比为 1.5Na₂O:0.5Al₂O₃:1SiO₂:128H₂O, 于 90 ^oC 晶化 12 h. 另外, 研究了水溶液中 Cd²⁺离子在该分子筛上的吸附行为, 考察了吸附时间、Cd²⁺离子浓度、溶液初始 pH 值以及分子筛用量对吸附行为的影响. 结果表明, A 型分子筛对水中 Cd²⁺离子吸附 90 min 时达平衡, 吸附过程符合准二级动力学速率方程; 溶液初始 pH = 6 时, Cd²⁺离子的去除率最高, 吸附等温线可以用 Langmuir 和 Freundlich 模型来描述, 最大吸附容量可达 161.3 mg/g, 最佳吸附剂用量为 1.00 g/L.

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