Immobilization of Metalloporphyrin on Functionalized Magnetic Nanoparticles as a Catalyst in Oxidation of Cyclohexene: Novel Modified Fe3O4 Nanoparticles with Triethoxysilane Agent

Magnetic nanoparticles, Fe₃O₄, have been prepared and functionalized by (N-(3-(triethoxysilyl)propyl)isonicotinamide) and characterized by infrared spectroscopy, thermal analysis (TGA/DTA), X-ray powder diffraction, scanning electron microscopy, elemental analysis and BET surface area measurement. The functionalized Fe₃O₄ nanoparticles were used as a support to anchor metalloporphyrin. Application of immobilized metalloporphyrin as a heterogeneous catalyst in the oxidation of cyclohexene was explored. Effect of various parameters such as solvent and temperature on immobilization process and also various parameters (solvent, time, oxidant and axial group effect) on oxidation of cyclohexene has been investigated. The result showed that the immobilized metalloporphyrin on functionalized magnetic nanoparticles is an efficient and reusable catalyst for oxidation of cyclohexene.     

CoPc/MCM-41催化氧化环己烯合成环己烯酮

以MCM-41型介孔分子筛为载体,酞菁类金属大环配合物为活性组分合成出了CoPc/MCM-41型催化剂,并对其结构进行了表征。红外、XRD和热重分析证实,催化剂活性组分负载后其热稳定性明显增加。进而以自制的CoPc/MCM-41为催化剂,对分子氧氧化环己烯制备环己烯酮的工艺条件进行了探索,结果表明,在催化剂用量120 mg(5 mL环己烯),反应温度55℃,反应时间8 h,二氯乙烷为溶剂的条件下,环己烯酮的单程产率可达24.2%,催化剂可分离回收,回收催化剂重复使用5次后,活性下降约3%。     

Catalytic Oxidation of Cyclohexane and Cyclooctene over a New Metalloporphyrin Supported on VOPO4 Catalyst

In this work, we report the use of oxovanadium phosphate as support of the 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin iron (III) chloride (Fe(TDCPP)Cl) and of the 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin manganese (III) chloride (Mn(TDCPP)Cl) catalysts for cyclohexane and cyclooctene oxidations by iodosylbenzene. The catalytic results have shown that oxovanadium phosphate support is suitable for metalloporphyrin catalysts leading to an efficient system for the cyclooctene epoxidation and very selective for cyclohexane hydroxylation.     

Co-Zr/MCM-41催化氧化石蜡的研究

从催化氧化石蜡生产特种蜡及其添加剂的角度出发,采用Co/SiO2、Co/MCM-41、Zr/MCM-41、Co-Zr/MCM-41为催化剂,用空气作氧化剂,对石蜡氧化进行了实验研究。考察了金属负载量对催化性能的影响、不同负载金属催化剂的石蜡氧化活性比较、Co、Zr含量对Co-Zr/MCM-41活性的影响。实验结果表明,以MCM-41作为载体制备钴负载量为12%、锆负载量为3%的复合氧化物为催化氧化反应的催化剂,在氧化温度为140℃、氧化时间为5 h、空气流量为0.7 L/min、催化剂用量为2%的最经济反应条件下可得到高酯酸比的氧化蜡产品。     

Extraction of Ultra Trace Amounts of Palladium on 9-Acridinylamine Functionalized SBA-15 and MCM-41 Nanoporous Silica Sorbents

The application of the modified MCM-41 and SBA-15 nanporous silicas in extraction of trace amounts of palladium is investigated and developed. Surface of nanoporous silicas, MCM-41 and SBA-15, were modified with 9-acridinylamine ligand and then utilized as solid-phase sorbents for the extraction of palladium. Different experimental conditions such as pH, flow rates of the sample, and eluent solution were studied. The type and the smallest amount of eluent for elution were optimized and the breakthrough volume and the influence of various cationic interferences on the adsorption was investigated. The recovery values in this method are greater than 95% and 98.5%. The obtained limits of detections (LOD) are lower than 0.17 ng mL^?1 and 0.15 ng mL^?1 for SBA-15 and MCM-41, respectively. The pre-concentration factors were calculated to be more than 193 and 187.5 for SBA-15 and MCM-41, respectively. The relative standard deviations (RSD) of the method are lower than 4% and 1.5%, and the adsorption capacities were also obtained to be more than 170 mg g^?1 and 195 mg g^?1 for SBA-15 and MCM-41, respectively. The proposed procedure was applied on real samples and the amount of palladium was successfully derived.     

Catalytic Oxidation of Cyclohexene by H2O2 Over Pd(II)-Complex Catalyst in a Heterogeneous System

Catalysis Letters - The grafting of 4, 5-diazofluorene-9-one (DAFO) to the mesoporous silica functionalized with aminopropyltriethoxysilane resulted in a material capable of absorbing Pd(II) to...     

Functionalized Bilayer Membranes as Artificial Transaminase: Modification of the Active Site and Its Consequence in Catalytic Efficiency

The transamination reaction of l-phenylalanine with pyruvate as catalyzed by the artificial transaminase formed with synthetic bilayer aggregates was examined in aqueous media under mild kinetic conditions. Each catalyst system was constructed with a combination of a synthetic peptide lipid, a hydrophobic vitamin B₆ derivative, and metal ions. Modification of the active site in the present artificial transaminase was performed by changing a combination of molecular components constituting the catalytic system. While the catalytic activity was scarcely influenced by differences in aggregate structure, single- or multi-walled bilayer, and in copper-(II) concentration, molecular structures of the hydrophobic vitamin B₆ and an amino acid residue of the peptide lipid had significant effects on the reactivity.     

微波辐射下以MCM-48负载磷钨杂多酸催化合成苯甲醛乙二醇缩醛

用介孔载体负载磷钨杂多酸作催化剂,在微波辐射下催化合成了苯甲醛乙二醇缩醛,考察了微波辐射功率、微波辐射时间、催化剂种类、原料配比、催化剂用量对产率的影响。实验表明:当微波辐射输出功率为600W,反应温度为80℃,辐射时间为10 m in,催化剂用量约为反应物总质量的2%,n(苯甲醛)∶n(乙二醇)=1∶1.5,产率可达75.61%。     

Highly Diluted Copper in a Silica Matrix as Active Catalyst for Propylene Oxidation to Acrolein

The use of copper phthalocyanine as the copper precursor extremely diluted in a silica matrix (below 0.1%) was found to result in a very active catalyst in the selective oxidation of propene by oxygen to produce acrolein with selectivities above 50% and yields of ~10%.     

催化精馏塔内催化剂床层润湿率研究

在９０ｍ ｍ 的有机玻璃塔内,用空气－水系统,通过稳态降阶示踪法对催化精馏塔内催化剂床层的润湿特性进行研究。得到润湿率随操作参数的变化曲线,并关联了润湿率随液体流速和气体流速变化的经验关联式, 为催化剂床层润湿率的预测提供依据。     

氨基功能化MCM-48介孔材料的制备及选择性吸附卷烟主流烟气中氰化氢的性能

以纯硅MCM-48为原料合成了表面氨基功能化的MCM-48材料,进行了X射线衍射(XRD)、氮气吸附、SEM扫描电镜和FT IR红外光谱等表征。FT IR和元素分析的结果表明,3-氨基丙基三乙氧基硅烷通过与纯硅MCM-48表面的Si-OH基团反应,使氨基嫁接在纯硅Si-MCM-48表面。XRD和N2吸附说明纯硅MCM-48在嫁接氨基后仍保持Ia3d立体结构,但与纯硅MCM-48相比,氨基功能化的MCM-48的比表面积、孔容和孔径均有所下降。将氨基功能化的MCM-48作为吸附剂加入卷烟的过滤嘴,对于主流烟气中氰化氢(HCN)具有很好的选择性吸附功能。     

湿式催化氧化催化剂及其活性组分流失控制的研究

湿式催化氧化技术是一种处理高浓度、难降解有机废水的高效、可行的技术,但是在使用过程中,活性组分易流失,在工业化应用中带来催化活性降低、使用寿命变短、投资成本增高等问题。文中介绍了湿式催化氧化技术及催化剂研究,着重讲述催化剂流失机理、影响因素以及提高催化剂稳定的方法,同时对相关实验和成果也做了介绍。     

硅胶固载离子液体催化剂的制备及在酯化反应中的应用

为了减少离子液体用量及解决催化剂分离问题,该文采用溶胶-凝胶法制备出一种硅胶固载Brφnsted酸性离子液体催化剂{[Hmim]TsO/silicagelw([Hmim]TsO)=62%},用DRFITS、FTRaman、BET对其进行了表征,结果表明,离子液体已较好地固载于硅胶上,催化剂比表面积为51.15m2/g。将其应用于催化合成醋酸丁酯反应,较佳反应条件为:95℃,n(丁醇)∶n(醋酸)=1.2∶1,离子液体用量为反应物总质量的5.6%,反应时间6h,酯化率可达94%。与单纯离子液体[Hmim]TsO催化效果相比,离子液体质量减少72%,酯化率提高了8.9%,催化剂易分离,循环使用6次后,酯化率仍可达到83.3%。     

用氨基化硅胶和甲醛固定脂肪酶的研究

以甲醛为偶联剂,将脂肪酶固定在3-氨基丙基硅胶上。以差热分析法测试了自然酶和固定化酶的热稳定性,并研究了反应介质的温度和pH值对自然酶和固定化酶活性的影响。自然酶和固定化酶的最适pH值都在7.5附近,但固定化酶的最适温度较自然酶低。另外,还测试了固定化酶在37℃的磷酸盐缓冲溶液中贮存的稳定性,与自然酶相比其贮存的稳定性有显著的提高,同时发现固定化酶在37℃的磷酸盐缓冲溶液中有一个恢复活力的过程。     

Synthesis of ZnFe2O4 Nanoparticles Confined Within Nanoporous Silica Using Trinuclear Oxo-centered Complex: Inorganic Complexes as a Precursor for the Preparation of Magnetic Nanoporous Silica

MCM-48 Nanoporous silica (Mobil Composition of Matter, #48) was synthesized and functionalized by pyridine groups. The formation of this functionalized nanoporous silica was confirmed by elemental analysis, low angle x-ray powder diffraction and N₂ adsorption. The trinuclear oxo-centered Fe₂Zn(μ₃-O)(CF₃COO)₆(H₂O)₃ cluster was synthesized and immobilized inside the pyridine functionalized MCM-48 pores. The immobilization of this cluster was confirmed by IR spectroscopy and flame atomic adsorption spectroscopy. Fe₂ZnO₄ nanoparticles were confined within the nanoporous silica pores by thermolysis of the immobilized Fe₂Zn(μ₃-O)(CF₃COO)₆(H₂O)₃ cluster and were characterized by high angle X-ray powder diffraction and high resolution transmission electron microscopy. This method is suitable for the one-pot preparation of Fe₂ZnO₄ confined nanoporous silica.     

金属卟啉/金属盐复合催化氧化合成对甲氧基苯甲醛

文章采用金属卟啉/金属盐作为复合催化剂,氧气作为氧源,以对甲氧基甲苯为原料催化氧化合成了对甲氧基苯甲醛。实验中探讨了复合催化剂和反应条件对反应体系的影响,结果表明:反应条件为对甲氧基甲苯初始浓度2 mol/L,催化剂用量0.05 mmol/L,反应温度90℃,反应压力0.4 MPa,乙腈17.5 m L,反应时间8 h。最终的产率可以达到21.6%。