金属酞菁负载纤维对空气中含硫化合物的催化氧化

合成了八羧基钴酞菁(Co-oaPc)和八羧基铁酞菁(Fe-oaPc) 两种水溶性酞菁,将这两种酞菁及两者按摩尔比为1:1混合的酞菁分别负载到阳离子改性的粘胶纤维上,制得3种金属酞菁负载纤维.测试其在溶液中对巯基乙醇的催化氧化性能发现这些负载纤维均具有催化氧化能力,而混合金属酞菁负载纤维的催化活性最高;通过在空气中对甲硫醇和H2S的消除实验,得到的结论相同.ESR测试表明,混合酞菁负载纤维可以观测到10个Co2 和Fe3 的超精细分裂线,表明其聚集的趋势较两种酞菁单独负载时弱,有利于甲硫醇和硫化氢分子与酞菁发生轴向配位,从而提高其催化活性.     

酞菁钴负载镁铝水滑石对甲基橙的氧化脱色

通过共沉淀法制备了Mg/Al物质的量比为3∶1的镁铝水滑石,并将其作为载体负载磺化酞菁钴制得新型功能材料酞菁钴负载水滑石(CoPcTs-LDH)。通过红外和热重分析表征了CoPcTs-LDH,研究了CoPcTs-LDH/H2O2对100mL 10mg/L甲基橙的氧化脱色。实验结果表明,在25～37℃、pH值为3～9、反应7h后甲基橙的剩余率均低于30%;反应过程符合一级动力学模型,阿伦尼乌斯活化能Ea=57.64kJ/mol;反应过程中羟基自由基发挥了重要作用;CoPcTs-LDH在重复使用5次后对甲基橙仍有很好的氧化脱色能力,具有较高的重复使用性能。     

活性碳纤维负载钴酞菁催化氧化2-巯基乙醇的研究

将四（2,4-二氯-1,3,5-三嗪基）氨基钴酞菁以共价键形式键合在活性碳纤维（ACF）载体上,制得了活性碳纤维负载钴酞菁催化剂（ACF-CoPc）,采用热重分析、原子吸收光谱和氮气等温吸附法对其进行了表征。原子吸收光谱测得金属酞菁的负载量为5.26μmol/g。氮气等温吸附法测得ACF-CoPc的比表面积为1235.9m2/g,孔径分布以2nm左右的小孔为主。以2-巯基乙醇为催化对象,采用超高效液相色谱研究了ACF-CoPc的催化氧化性能。结果表明ACF-CoPc对2-巯基乙醇具有很好的催化氧化性能,反应4h时对2-巯基乙醇的去除率高达100%,氧化产物为2,2’-二硫二乙醇。而且催化剂ACF-CoPc经6次循环使用后,对2-巯基乙醇的去除率没有持续下降,这表明该催化剂具有良好的重复使用性。     

铁锌复合金属有机碳材料对酸性橙7的吸附作用研究

基于铁锌金属有机骨架,制备铁锌复合金属有机碳材料(ZnO/Fe_3O_4@C),并进行了ZnO/Fe_3O_4@C吸附酸性橙7(AO7)的研究,考察初始pH、AO7初始浓度、ZnO/Fe_3O_4@C用量等因素对AO7吸附量的影响,并分析了吸附材料对AO7的吸附动力学模型。结果表明,pH对吸附效果有较大的影响,ZnO/Fe_3O_4@C在酸性条件下显示出了良好的吸附性能,在pH=3.0,AO7初始浓度在10～30μmol/L变化时,单位吸附量随着AO7浓度的增加而增大;在pH=3.0,AO7浓度为20μmol/L,ZnO/Fe_3O_4@C用量为0.5g/L条件下,吸附效果最好,ZnO/Fe_3O_4@C对AO7的降解率可达到92.90%。研究结果还表明,吸附动力学符合假二级动力学模型,化学吸附是其主要速度控制步骤。     

含金属酞菁的再生蚕丝蛋白肽粉末的制备及其抗菌消臭性

将蚕丝蛋白用有机无机混合溶液溶解并透析制成蚕丝蛋白肽水溶液,将此水溶液与用固相法合成的锌金属酞菁的醇溶液进行物理共混制备含金属酞菁的再生蚕丝蛋白肽粉末.对相关化合物进行了紫外光谱、红外光谱表征,显示出再生蚕丝蛋白肽与锌金属酞菁能在大分子层面上进行结合.试验了相关化合物对金黄葡萄球菌、大肠杆菌的抗菌作用以及对氨气的消除作用,结果表明,混合金属酞菁的再生蚕丝蛋白肽具备抗菌作用,并能在约6h内将氨气浓度降解为0.     

5A分子筛载CuO对甲基橙的催化湿式过氧化氢氧化

以三水硝酸铜和5A分子筛为原料,采用湿法浸渍法制备了CuO-5A催化剂,采用扫描电镜、X射线衍射仪和红外光谱仪对其进行分析表征,并将其用于处理甲基橙模拟废水。考察材料种类(5A+H₂O₂,20%CuO-5A+H₂O₂,H₂O₂)、铜负载量、pH值、催化剂投加量、温度等因素对催化效果的影响,并测定催化剂的稳定性,同时采用准一级动力学模型进行拟合分析。结果表明,CuO已成功负载在5A分子筛表面,采用20%的CuO-5A对甲基橙的催化湿式氧化效果最好。在甲基橙初始浓度为50 mg/L、材料投加量为0.6 g、pH值为2、温度为70 ℃条件下,第一次、第二次和第三次使用的CuO-5A在60 min时对甲基橙的转化率分别为97.9%、92.3%和90.5%。不同温度下CuO-5A对甲基橙的催化湿式氧化行为可用准一级动力学方程来描述,拟合曲线展示了两个线性阶段,其中第二阶段活化能为50.35 kJ/mol。     

酞菁钴/MCM-41的制备及其可见光催化性能

以MCM-41分子筛为载体,采用浸渍法将酞菁钴负载到分子筛上以氙灯为光源降解甲基橙溶液。对负载型酞菁钴催化剂进行FT-IR、XRD、SEM表征,结果表明所制催化剂负载效果良好,且分子筛结构未发生改变。以甲基橙溶液为模拟处理对象,研究催化剂的催化性能,考察了光照、酞菁钴负载、催化剂用量等因素对催化效果的影响。结果表明,氧气充足时,在光照条件下、0.04g负载型酞菁钴催化剂处理200mL的0.05g/L甲基橙溶液能够有很好的处理效果,2h降解率能够达到98.3%,且重复利用4次后降解率仍能达到90%。     

负载新型酞菁纤维素纤维的制备及催化氧化性能

首先采用丁二酸酐和顺丁烯二酸酐改性氨基钴酞菁制得两种新型水溶性钴酞菁,然后将这两种新型水溶性钴酞菁负载到纤维素纤维上,制得新型高分子催化剂,并选用巯基乙醇和H2O2作为底物来考察负载酞菁纤维素纤维的催化氧化活性。实验结果表明,两种高分子催化剂对巯基乙醇具有良好的催化氧化活性和催化分解H2O2的能力。     

金属酞菁的微波合成研究进展

微波合成与传统合成方法相比因具有效率高、节省能源、产品纯度高、安全等优点已被广泛应用。以金属酞菁的存在形式分类,分别从金属酞菁单体、金属酞菁聚合体、改性金属酞菁及金属酞菁复合材料4方面概述了近几年国内外对金属酞菁微波合成的研究进展,并与传统的合成方法进行了对比,展望了微波合成的发展前景。     

苯乙烯-二乙烯苯树脂负载双核钴酞菁对巯基乙醇的催化性能

双棱钴酞菁(Co2Pc2)以共价键负载到苯乙烯-二乙烯苯树脂(resin)上得到一种新型的催化功能性材料(resin-Co2Pc2).考察了pH、催化剂量和温度对resin-Co2Pc2催化巯基乙醇的影响.实验结果表明,resin-Co2Pc2在pH=11儿时催化活性达到最大;催化活性随反应温度升高而提高,此催化反应为吸热反应,而且resin-Co2Pc2经多次重复使用后其催化活性基本保持不变,具有很好的重复使用性能.     

Fabrication of tunnelling barriers by oxidation in hydrogen peroxide

One of the major experimental difficulties in electron tunnelling work is the preparation of very thin insulating barriers. This paper describes a method based on oxidation of the substrate in hydrogen peroxide. Good results have been obtained with gallium and tin, and the technique may be useful for other metals as well.     

Catalytic degradation of explosives with goethite and hydrogen peroxide

Goethite (alpha-FeOOH), one of soil contents, can be dissolved in acidic water to produce ferrous ions initiating Fenton reaction with hydrogen peroxide to degrade explosive. In this study, a series of catalytic degradation of nitro aromatic explosives, namely picric acid (PA) and ammonium picrate (AP) have been investigated using the FeOOH/H2O2 process. The controlling factors, such as adsorption of goethite dosage, hydrogen peroxide concentration and UV-light exposure on the oxidation of nitro aromatic explosives were investigated. The results showed that target compounds were adsorbed on the surface of goethite while the oxidation was proceeding. Furthermore, inhibition effect of nitro aromatic intermediates on the reaction was also discussed. A half-life kinetic model has been proposed to predict the half-lives of explosive oxidation in the goethite/H2O2 system.     

Wet oxidation of acid brown dye by hydrogen peroxide using heterogeneous catalyst Mn-salen-Y zeolite: a potential catalyst

Catalytic wet hydrogen peroxide oxidation of acid dye has been explored in this study. Manganese(III) complex of N,N'-ethylene bis(salicylidene-aminato) (salenH(2)) has been encapsulated in super cages of zeolite-Y by flexible ligand method. The catalyst has been characterized by FT-IR, XRD, TG/DTA and nitrogen adsorption studies. The effects of various parameters such as pH, catalyst and hydrogen peroxide concentration on the oxidation of dye were studied. The results indicate that after 20 min at 30 degrees C, 0.175 M H(2)O(2) and 3g/L catalyst, about 90% dye removal was obtained. These studies indicate that manganese-salen complex immobilized on zeolite framework can act as a good heterogeneous catalyst for removal of dye from wastewaters.     

Photo-assisted oxidation of an oily wastewater using hydrogen peroxide

The primary objective was to study the purification of an oily wastewater from a lubricant production unit using ultraviolet irradiation and hydrogen peroxide. The influence of hydrogen peroxide concentration, initial pH of the solution and of the addition of ferric ions on the chemical oxygen demand (COD) was examined. In each case, the concentration of the compounds contained in the oily wastewater was determined. It was shown that a 20-45% COD removal was achieved with 830-1660 mg l(-1) H(2)O(2). Gas chromatography-mass spectrometry analysis showed that the organic compounds of the wastewater decomposed to organic acids that were very resistant to photo-oxidation. Among these compounds, ethylene glycol remained almost unchanged by the attack from hydroxyl radicals. Acidic pH and Fe(III) addition enhanced significantly the photo-oxidation of the wastewater.     

A novel potentiometric hydrogen peroxide sensor based on pKa changes of vinylphenylboronic acid membranes

A potentiometric hydrogen peroxide (H₂O₂) sensing scheme was developed using arylboronic acid as the electrode modifier. It is well-known that both aliphatic and aryl boronic acid undergo electrophilic displacement reaction with H₂O₂. This reaction involves replacement of boronic acid by the hydroxyl group of peroxide resulting in a change in pK_a value that can be exploited for sensing of H₂O₂. Vinylphenylboronic acid (VPBA) ink was prepared using Nafion as the binder and it was drop cast on an electrode surface. Morphology of the modified electrode was analysed using scanning electron microscopy (SEM). The present modifier exhibited a linear relationship between the difference in electrode potential (?Ep) vs. [H₂O₂] with a Nernstian slope of 26 ± 2 mV in the concentration range of 10^? 1–10^? 5 M. Application of the VPBA modified electrode for hydrogen peroxide sensing was studied in an industrial dye-bleach effluent.     

Catalytic wet air oxidation of chlorophenols over supported ruthenium catalysts

A series of noble metal (Pt, Pd, Ru) loaded zirconia catalysts were evaluated in the catalytic wet air oxidation (CWAO) of mono-chlorophenols (2-CP, 3-CP, 4-CP) under relatively mild reaction conditions. Among the investigated noble metals, Ru appeared to be the best to promote the CWAO of CPs as far as incipient-wetness impregnation was used to prepare all the catalysts. The position of the chlorine substitution on the aromatic ring was also shown to have a significant effect on the CP reactivity in the CWAO over 3wt.% Ru/ZrO(2). 2-CP was relatively easier to degradate compared to 3-CP and 4-CP. One reason could be the higher adsorption of 2-CP on the catalyst surface. Further investigations suggested that 3wt.% Ru/ZrO(2) is a very efficient catalyst in the CWAO of 2-CP as far as high 2-CP conversion and TOC abatement could still be reached at even lower temperature (393K) and lower total pressure (3MPa). Additionally, the conversion of 2-CP was demonstrated to increase with the initial pH of the 2-CP solution. The dechlorination reaction is promoted at higher pH. In all cases, the adsorption of the reactants and the reaction intermediates was shown to play a major role. All parameters that would control the molecule speciation in solution or the catalyst surface properties would have a key effect.     

Olive mill wastewater degradation by Fenton oxidation with zero-valent iron and hydrogen peroxide

The degradation of olive mill wastewater (OMW) with hydroxyl radicals generated from zero-valent iron and hydrogen peroxide has been investigated by means of chemical oxygen demand (COD) and phenolic compounds analyses. The effects of the H2O2 dose, the pH and the organic matter concentration have been studied. The optimal experimental conditions were found to have continuous presence of iron metal, acid pH (2.0-4.0), and relatively concentrated hydrogen peroxide (9.5M). Coloration of OMW disappeared and phenolic compound decreased to 50% of initial concentration after 3h reaction time. The application of zero-valent Fe/H2O2 procedure permitted high removal efficiencies of pollutants from olive mill wastewater. The results show that zero-valent Fe/H2O2 could be considered as an effective alternative solution for the treatment of OMW or may be combined with a classical biological process to achieve high quality of effluent water.