碳纤维负载钴酞菁降解染料的研究

采用碳纤维负载钴酞菁和苯磺酸钠制备出对活性染料具有高效降解的新型催化功能纤维(CoPc-CF),讨论了温度、pH对CoPc-CF/H2O2体系催化氧化染料性能的影响,并研究了在无机盐(NaCl、Na2SO4)和异丙醇存在下对染料催化降解速率的影响,以及不同活性染料对其催化降解性能的影响。结果表明:提高温度,能明显促进染料的氧化降解;CoPc-CF/H2O2体系在中性和弱碱性中都具有较好的催化降解性能;NaCl和Na2SO4的存在对CoPc-CF/H2O2体系的催化氧化没有影响,而异丙醇的加入有明显地抑制作用;CoPc-CF/H2O2体系对不同活性染料催化氧化速率有很大的影响。     

碳纳米纤维负载钴酞菁催化分解双氧水的研究

通过将四氨基钴酞菁(CoTAPc)以共价键方式负载到碳纳米纤维(CNF)上,制备得到了碳纳米纤维负载钴酞菁催化剂(CoTAPc-CNF)。研究了CoTAPc-CNF对H2O2的催化分解性能,考察了不同底物浓度、pH和温度对CoTAPc-CNF催化分解H2O2的影响。结果表明:随着底物浓度的增加,CoTAPc-CNF催化分解H2O2的速率加快;在碱性条件下,CoTAPc-CNF具有较好的催化分解H2O2性能;温度越高,CoTAPc-CNF催化分解H2O2越快,并求得该催化反应的活化能为17.917kJ/mol。     

偶氮染料的金属酞菁负载棉纤维脱色降解北大核心

将铁酞菁(Fe Pc)和钴酞菁(Co Pc)分别负载到棉纤维上,制备了催化功能纤维(Fe Pc/F、Co Pc/F),并研究其对四种偶氮染料的催化脱色性能。结果表明,H2O2的存在,能有效提高催化功能纤维对这四种染料的脱色率。中性和弱碱性条件下,催化功能纤维能有效氧化降解活性艳红3BSN和酸性黄G。     

偶氮染料的金属酞菁负载棉纤维脱色降解

将铁酞菁(Fe Pc)和钴酞菁(Co Pc)分别负载到棉纤维上,制备了催化功能纤维(Fe Pc/F、Co Pc/F),并研究其对四种偶氮染料的催化脱色性能。结果表明,H2O2的存在,能有效提高催化功能纤维对这四种染料的脱色率。中性和弱碱性条件下,催化功能纤维能有效氧化降解活性艳红3BSN和酸性黄G。     

锦纶纤维负载钴酞菁催化氧化酸性红G的研究

将可反应的水溶性钴酞菁(Co-TDTAPc)负载到锦纶纤维上制备了催化功能纤维(F-CoTDTAPc)。利用紫外/可见分光光度法对F-CoTDTAPc/H2O2体系催化氧化酸性红G进行研究,考察了氧化剂质量浓度、pH值、反应温度等对F-CoTDTAPc/H2O2体系氧化降解酸性红G的影响。结果表明,F-CoTDTAPc在H2O2存在下能快速催化氧化酸性红G,并具有较好的原位再生能力。气质联用分析结果表明,酸性红G分子已被氧化降解为可生物降解的脂肪酸类化合物,酸性红G在反应过程中发生了深度氧化降解。     

金属酞菁/过氧化氢/四乙酰乙二胺体系对染色棉织物的剥色性能研究

研究染色棉织物CoTSPc/H2O2/TAED催化氧化剥色剂。将四磺酸基钴酞菁(CoTSPc)吸附到活性艳红M-3BE染色后的棉织物上,与氧化剂过氧化氢(H2O2)以及过氧化氢活化剂四乙酰乙二胺(TAED)构成CoTSPc/H2O2/TAED催化氧化剥色体系,对染色棉织物进行剥色实验。研究pH值、CoTSPc浓度、H2O2浓度、TAED浓度、活化时间、剥色温度、剥色时间等因素对剥色效果的影响。通过测试染色棉织物剥色前后的K/S值下降率和断裂强力保留率对剥色效果进行综合评价。同时在最佳剥色条件下对另外4种活性染料染色后的棉织物进行剥色实验。结果表明:CoTSPc/H2O2/TAED催化氧化剥色体系对部分活性染料染色后的棉织物的剥色效果较好,且保留了较为理想的断裂强力。     

酞菁负载纤维素纤维对活性染料的氧化脱色

 为解决染料废水污染日益严重的问题,将钴酞菁负载到纤维素纤维上制备非均相催化剂钴酞菁/纤维素纤维(Co-TDTAPc-F),采用紫外可见光谱仪研究该非均相催化剂对6种不同结构活性染料的氧化脱色性能。结果表明:Co-TDTAPc-F对6种染料有一定的富集作用,而Co-TDTAPc-F/H2O2体系能有效地对这6种染料进行氧化脱色,而且反应60 min后染料的脱色率均超过85%,同时发现染料分子结构中含有的磺酸基数量、染料对纤维的直接性均会影响染料的脱色效果。     

碳纤维负载铁酞菁催化氧化有机污染物的性能

利用4-氨基吡啶对碳纤维(CF)进行表面改性,然后通过轴向配位将铁酞菁(FePc)负载到改性碳纤维上,得到碳纤维负载铁酞菁催化材料(CF-py-FePc),并利用电感耦合等离子光谱发生仪测定铁酞菁负载量。分别以酸性红1和甲醛为底物研究其催化和电催化性能,结果表明:CF-py-FePc能有效催化活化双氧水氧化酸性红1,并能高效电催化降解甲醛,且具有良好的循环使用性能。     

从化纤企业排放废气中净化H_2S的无废料工艺

净化排放废气中的H_2S,实际上是采用苯二酚和酞菁钴为催化剂的氧化催化过程(用碱性苯二酚和碱性酞菁)。这些氧化催化过程,对用相同构造形式的设备和用碳酸钠与碳酸氢钠液作缓冲液吸收H_2S都是一样的。所不同的是在相同的pH值吸收液中,被吸收的H_2S氧化到元素硫的选择性和催化剂的活性。酞菁钴具有较高的催化活性,即使在溶液中含量较少,也能实现     

钴酞菁/PAN纳米纤维催化H_2O_2对酸性红G的降解

将钴酞菁和聚丙烯腈一起溶解,通过静电纺丝的方式制备出钴酞菁/PAN纳米纤维。选择偶氮染料酸性红G作为模型底物,环境友好型的双氧水作为氧化剂,研究了温度、pH值、氧化剂初始浓度、催化剂用量、印染助剂等对催化体系的影响,探讨了钴酞菁和PAN的重复使用性能和催化机理。结果表明:温度的升高和氧化剂初始浓度的加大,都能加快底物的去除速率;异丙醇和氯化钠对催化体系的活性没有影响,推测体系是由非羟基自由基主导的反应;此外,催化剂多次循环使用后,其活性并未出现明显下降。     

金属酞菁接枝纤维素纤维及其消臭性能

 采用顺丁烯二酸酐改性四氨基钴酞菁制备新型水溶性钴酞菁,并对其进行了元素分析和红外光谱表征。将金属酞菁接枝到纤维素纤维上制备功能纤维。在室温条件下,该功能纤维能有效去除甲硫醇和氨气,甲硫醇按催化氧化机理去除,而氨气按酸碱中和机理去除,2 h的去除率分别为69.7%和97.6%。     

催化氧化荧光法测定防腐剂苯甲酸

在pH8 的NaH2PO4-Na2HPO4 缓冲溶液中,Co2+ 催化KBrO3 氧化苯甲酸产生强荧光,建立催化氧化荧光法间接测定苯甲酸的新方法。在最优化条件下,苯甲酸质量浓度在5 × 10-7～3 × 10-5g/mL 范围内与荧光强度呈良好的线性关系,方法的检出限为2 × 10-8g/mL。对质量浓度为1 × 10-6g/mL 的苯甲酸标准溶液进行11 次平行测定,得相对标准偏差(RSD)为1.9%。该法应用于食醋及酱油中苯甲酸的测定,回收率为95.7%～101.6%,结果令人满意。     

苹果酒中模拟体系下非酶氧化与酶促氧化对聚合度影响的研究

以苹果酒中单酚含量较多的4种酚（儿茶素、表儿茶素、绿原酸和咖啡酸）为研究对象。在模拟苹果酒pH体系环境下，对其在非酶氧化和酶促氧化下聚合度的变化进行了研究。结果表明，在非酶氧化过程中，以儿茶素和表儿茶素的聚合反应为主，而在酶促氧化过程中。则是以绿原酸和咖啡酸的聚合反应为主。     

云南核桃抗氧化功效成分氧化稳定性研究

为了解核桃抗氧化功效成分黄酮、总酚、维生素E的贮藏稳定性及其与核桃氧化劣变的相关性,采用Schaal烘箱法对云南核桃进行氧化加速试验,对核桃油的氧化卫生指标和核桃仁功效成分(总酚、黄酮、维生素E)进行了测定和分析研究.结果表明:在前29 d核桃氧化速度较慢,总酚、黄酮、维生素E含量迅速下降,稳定性差;29 d后核桃氧化速度加快,总酚、黄酮、维生素E含量变化较小.核桃仁总酚和黄酮稳定性与核桃油过氧化值呈显著负相关,VE稳定性与过氧化值呈极显著负相关.总酚、黄酮、维生素E对核桃的氧化具有很好的抗氧化保护作用,其中维生素E的抗氧化保护作用最大.     

莲藕采后生理及保鲜技术研究进展

指出莲藕在贮藏过程中发生褐变和衰老的主要原因是组织内部的多酚氧化酶催化氧化酚类物质产生黑色素。概述了近年来莲藕多酚氧化酶的催化反应动力学特性;pH值、温度、金属离子对莲藕多酚氧化酶活性的影响;莲藕采后多酚氧化酶活性与组织褐变、呼吸及衰老之间的关系;莲藕褐变和衰老的抑制及其保鲜技术等方面的研究进展。     

Highly efficient decomposition of organic dyes by aqueous-fiber phase transfer and in situ catalytic oxidation using fiber-supported cobalt phthalocyanine

A novel metallophthalocyanine derivative, cobalt tetra (2,4-dichloro-1,3,5-triazine) aminophthalocyanine (Co-TDTAPc), was prepared and immobilized on cellulosic fiber by covalent bond to obtain a supported oxidation catalyst (Co-TDTAPc-F). Co-TDTAPc-F/H202 system based on phase-transfer catalytic oxidation for decomposing dyes, including acid, reactive, and direct dyes, has been investigated thoroughly. Compared to traditional adsorption technologies and advanced oxidation processes (AOPs) for dye treatment, Co-TDTAPc-F/H202 combines the advantages of both and is more efficient and more effective. Azo dyes such as C. I. Acid Red 1 (AR1) can be quickly adsorbed onto/into the fiber from aqueous solution and decomposed in situ simultaneously in the presence of Co-TDTAPc-F and H2O2. It has been found that the reaction process is not affected by the visible light. Furthermore, it turns the negative effect of NaCl normally observed in homogeneous catalysis into positive one. The catalytic reaction can proceed at a wide pH range from acidic to alkaline. In 60 min, more than 98% of AR1 was eliminated at initial pH 2. In 90 min, about 40% of the carbon was found mineralized as determined by the analysis of the residual total organic carbon. The high-performance liquid chromatography result indicated that a substantial amount of the starting AR1 was converted to other organic products, while gas chromatography/mass spectrometry analysis showed the rest of the carbon existed mainly as small molecular biodegradable aliphatic carboxylic compounds such as oxalic acid, malonic acid, and maleic acid, etc. Co-TDTAPc-F is stable, causes no secondary pollution, and remains efficient in repetitive test cycles with no obvious degradation of catalytic activity.     

Autoxidation of Methyl Linoleate in Freeze-Dried Model Systems. 4. Effects of Metals and of Histidine in the Absence of Water

SUMMARY: Autoxidation of methyl linoleate dispersed on filter paper was studied in the dry state in the presence and absence of additives. Oxidation was followed volumetrically and by measuring the increase in conjugated dienes. Evaluation of the rate data indicates that added histidine is antioxidant in the very early stages of the oxidation and becomes prooxidant in the later stages. Increasing the concentration of histidine promoted an earlier appearance of its prooxidant effect. Cobalt chloride and manganese sulfate had a pronounced catalytic effect on the oxidation reaction in the model systems buffered to a high (8.0 and 9.0) but not to a low (4.0) pH. Histidine increased the catalytic activity of manganese but eliminated that of cobalt. Thin-layer chromatography showed that conditions under which histidine increased the prooxidant effect of manganese also resulted in the appearance of some decomposition products of histidine. These decomposition products may have catalytic activity.     

Application of spinel-type cobalt chromite as a novel catalyst for combustion of chlorinated organic pollutants

Various chromium-containing catalysts were tested for the total oxidation of trichloroethylene (TCE) as a model reaction for the catalytic combustion of chlorinated organic pollutants. A spinel-type cobalt chromite (CoCr2O4) among others was proven to be a very promising catalyst showing higher activity and higher CO2 selectivity than traditional alumina supported chromia. Even if both Cr3+ and Cr6+ species were observed on the surface of CoCr2O4, the Cr6+ species was stable under reducing environment. The presence of Cr3+-Cr6+ pair sites and the effect of redox treatments on the activity were investigated to explain the nature of possible active sites for TCE decomposition. Higher selectivity to CO2 of CoCr2O4 was ascribed to the abundance of its Cr3+ species, together with its activity for water gas shift reaction.     

Electrochemical reduction of carbon dioxide in an MFC-MEC system with a layer-by-layer self-assembly carbon nanotube/cobalt phthalocyanine modified electrode

Electrochemical reduction of carbon dioxide (CO(2)) to useful chemical materials is of great significance to the virtuous cycle of CO(2). However, some problems such as high overpotential, high applied voltage, and high energy consumption exist in the course of the conventional electrochemical reduction process. This study presents a new CO(2) reduction technique for targeted production of formic acid in a microbial electrolysis cell (MEC) driven by a microbial fuel cell (MFC). The multiwalled carbon nanotubes (MWCNT) and cobalt tetra-amino phthalocyanine (CoTAPc) composite modified electrode was fabricated by the layer-by-layer (LBL) self-assembly technique. The new electrodes significantly decreased the overpotential of CO(2) reduction, and as cathode successfully reduced CO(2) to formic acid (production rate of up to 21.0 ± 0.2 mg·L(-1)·h(-1)) in an MEC driven by a single MFC. Compared with the electrode modified by CoTAPc alone, the MWCNT/CoTAPc composite modified electrode could increase the current and formic acid production rate by approximately 20% and 100%, respectively. The Faraday efficiency for formic acid production depended on the cathode potential. The MWCNT/CoTAPc composite electrode reached the maximum Faraday efficiency at the cathode potential of ca. -0.5 V vs Ag/AgCl. Increasing the number of electrode modification layers favored the current and formic acid production rate. The production of formic acid was stable in the MFC-MEC system after multiple batches of CO(2) electrolysis, and no significant change was observed on the performances of the modified electrode. The coupling of the catalytic electrode and the bioelectrochemical system realized the targeted reduction of CO(2) in the absence of external energy input, providing a new way for CO(2) capture and conversion.