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Detection of Oxidants Such as Hydroxyl Radicals and Chlorine Electrogenerated on a BDD Electrode by Simple Methods
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作者 Konan Sylvestre Koffi Konan Martin Koffi +4 位作者 Foffié Thiery Auguste Appia Sahi Placide Sadia Kouakou Jocelin Kimou Souleymane Kone Lassiné Ouattara 《Advances in Chemical Engineering and Science》 CAS 2024年第4期173-187,共15页
The aim of this work is to detect electrogenerated hydroxyl radicals and chlorine by simple and less expensive methods. Preparative electrolyses of perchloric acid (HClO4) and sodium chloride (NaCl) were performed on ... The aim of this work is to detect electrogenerated hydroxyl radicals and chlorine by simple and less expensive methods. Preparative electrolyses of perchloric acid (HClO4) and sodium chloride (NaCl) were performed on a boron-doped diamond (BDD) electrode. The hydroxyl radicals were quantified indirectly by assaying the samples from the HClO4 (0.1 M) electrolysis with a 10−4 M potassium permanganate solution. The investigations showed that the amount of hydroxyl radicals depends on the concentration of HClO4 and the current density. As for chlorine, a qualitative determination was carried out. A mixture of the electrolyte solution of HClO4 (0.1 M) + NaI (0.2 M) + 2 mL of hexane, taken in this order, leads to a purplish-pink coloration attesting to the presence of Cl2. The same test was carried out with NaBr and NaI giving pale and very pale pink colourations, respectively, showing that the intensity of the colouration depends on the strength of the oxidant present. In addition, oxidants were detected during the electrooxidation of metronidazole (MNZ). The results showed the participation of electrogenerated hydroxyl radicals. The generation of chlorine has also been proven. Furthermore, the degradation leads to a chemical oxygen demand (COD) removal rate of 83.48% and the process is diffusion-controlled. 展开更多
关键词 ELECTROOXIDATION hydroxyl Radicals CHLORINE DETECTION
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Introducing hydroxyl groups to tailor the d-band center of Ir atom through side anchoring for boosted ORR and HER
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作者 Qing Lv Meiping Li +3 位作者 Xiaodong Li Xingru Yan Zhufeng Hou Changshui Huang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期144-151,I0005,共9页
Tuning the coordination atoms of central metal is an effective means to improve the electrocatalytic activity of atomic catalysts.Herein,iridium(Ir) is proposed to be asymmetrically anchored by sp-N and pyridinic N of... Tuning the coordination atoms of central metal is an effective means to improve the electrocatalytic activity of atomic catalysts.Herein,iridium(Ir) is proposed to be asymmetrically anchored by sp-N and pyridinic N of hydrogen-substituted graphdiyne(HsGDY),and coordinated with OH as an Ir atomic catalyst(Ir_(1)-N-HsGDY).The electron structures,especially the d-band center of Ir atom,are optimized by these specific coordination atoms.Thus,the as-synthesized Ir_(1)-N-HsGDY exhibits excellent electrocatalytic performances for oxygen reduction and hydrogen evolution reactions in both acidic and alkaline media.Benefiting from the unique structure of HsGDY,IrN_(2)(OH)_(3) has been developed and demonstrated to act as the active site in these electrochemical reactions.All those indicate the fresh role of the sp-N in graphdiyne in producing a new anchor way and contributing to promote the electrocatalytic activity,showing a new strategy to design novel electrochemical catalysts. 展开更多
关键词 Oxygen reduction reaction D-band center Graphdiyne hydroxyl group ELECTROCATALYSIS
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Modified electronic structure and enhanced hydroxyl adsorption make quaternary Pt-based nanosheets efficient anode electrocatalysts for formic acid-/alcohol-air fuel cells
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作者 Fengling Zhao Qiang Yuan +2 位作者 Siyang Nie Liang Wu Xun Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期142-150,共9页
Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet challenging.Herein,using visible light,a class of quaternary Pt_(1)... Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet challenging.Herein,using visible light,a class of quaternary Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)ultrathin nanosheets is fabricated and used as high-performance anode electrocatalysts for formic acid-/alcohol-air fuel cells.The modified electronic structure of Pt,enhanced hydroxyl adsorption,and abundant exterior defects afford Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C high intrinsic anodic electrocatalytic activity to boost the power densities of direct formic acid-/methanol-/ethanol-/ethylene glycol-/glycerol-air fuel cells,and the corresponding peak power density of Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C is respectively 129.7,142.3,105.4,124.3,and 128.0 mW cm^(-2),considerably outperforming Pt/C.Operando in situ Fourier transform infrared reflection spectroscopy reveals that formic acid oxidation on Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C occurs via a CO_(2)-free direct pathway.Density functional theory calculations show that the presence of Ag,Bi,and Te in Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)suppresses CO^(*)formation while optimizing dehydrogenation steps and synergistic effect and modified Pt effectively enhance H_(2)O dissociation to improve electrocatalytic performance.This synthesis strategy can be extended to 43 other types of ultrathin multimetallic nanosheets(from ternary to octonary nanosheets),and efficiently capture precious metals(i.e.,Pd,Pt,Rh,Ru,Au,and Ag)from different water sources. 展开更多
关键词 Pt-based nanosheets Modifiedelectronic structure Enhanced hydroxyl adsorption Formicacidand alcohol oxidation Direct liquid fuel cells
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Internal Polarization Field Induced Hydroxyl Spillover Effect for Industrial Water Splitting Electrolyzers
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作者 Jingyi Xie Fuli Wang +3 位作者 Yanan Zhou Yiwen Dong Yongming Chai Bin Dong 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期438-449,共12页
The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction(OER)are affinitive with hydroxyl adsorption.However,ability of the catalyst to capture hydroxyl and maintain the continuous... The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction(OER)are affinitive with hydroxyl adsorption.However,ability of the catalyst to capture hydroxyl and maintain the continuous supply at active sits remains a tremendous challenge.Herein,an affordable Ni2P/FeP2 heterostructure is presented to form the internal polarization field(IPF),arising hydroxyl spillover(HOSo)during OER.Facilitated by IPF,the oriented HOSo from FeP2 to Ni2P can activate the Ni site with a new hydroxyl transmission channel and build the optimized reaction path of oxygen intermediates for lower adsorption energy,boosting the OER activity(242 mV vs.RHE at 100 mA cm-2)for least 100 h.More interestingly,for the anion exchange membrane water electrolyzer(AEMWE)with low concentration electrolyte,the advantage of HOSo effect is significantly amplified,delivering 1 A cm^(-2)at a low cell voltage of 1.88 V with excellent stability for over 50 h. 展开更多
关键词 hydroxyl spillover effect Internal polarization field HETEROSTRUCTURE Oxygen reduction reaction Anion exchange membrane water electrolysis
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F-box only protein 2 exacerbates non-alcoholic fatty liver disease by targeting the hydroxyl CoA dehydrogenase alpha subunit 被引量:1
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作者 Zhi Liu Ning-Yuan Chen +2 位作者 Zhao Zhang Sai Zhou San-Yuan Hu 《World Journal of Gastroenterology》 SCIE CAS 2023年第28期4433-4450,共18页
BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive... BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is a major health burden with an increasing global incidence.Unfortunately,the unavailability of knowledge underlying NAFLD pathogenesis inhibits effective preventive and therapeutic measures.AIM To explore the molecular mechanism of NAFLD.METHODS Whole genome sequencing(WGS)analysis was performed on liver tissues from patients with NAFLD(n=6)and patients with normal metabolic conditions(n=6)to identify the target genes.A NAFLD C57BL6/J mouse model induced by 16 wk of high-fat diet feeding and a hepatocyte-specific F-box only protein 2(FBXO2)overexpression mouse model were used for in vivo studies.Plasmid transfection,co-immunoprecipitation-based mass spectrometry assays,and ubiquitination in HepG2 cells and HEK293T cells were used for in vitro studies.RESULTS A total of 30982 genes were detected in WGS analysis,with 649 up-regulated and 178 down-regulated.Expression of FBXO2,an E3 ligase,was upregulated in the liver tissues of patients with NAFLD.Hepatocyte-specific FBXO2 overexpression facilitated NAFLD-associated phenotypes in mice.Overexpression of FBXO2 aggravated odium oleate(OA)-induced lipid accumulation in HepG2 cells,resulting in an abnormal expression of genes related to lipid metabolism,such as fatty acid synthase,peroxisome proliferator-activated receptor alpha,and so on.In contrast,knocking down FBXO2 in HepG2 cells significantly alleviated the OA-induced lipid accumulation and aberrant expression of lipid metabolism genes.The hydroxyl CoA dehydrogenase alpha subunit(HADHA),a protein involved in oxidative stress,was a target of FBXO2-mediated ubiquitination.FBXO2 directly bound to HADHA and facilitated its proteasomal degradation in HepG2 and HEK293T cells.Supplementation with HADHA alleviated lipid accumulation caused by FBXO2 overexpression in HepG2 cells.CONCLUSION FBXO2 exacerbates lipid accumulation by targeting HADHA and is a potential therapeutic target for NAFLD。 展开更多
关键词 F-box only protein 2 Nonalcoholic fatty liver disease The hydroxyl CoA dehydrogenase alpha subunit Liver steatosis Ubiquitination Lipid accumulation
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A Comparative Study of the Hydroxyl Value and Iodine Value in Polyoxyl Stearyl Ether in United States Pharmacopeia Specifications
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作者 Alyssa Beres Yusuf Yildiz 《American Journal of Analytical Chemistry》 2023年第9期410-419,共10页
The iodine value (iodine number) and hydroxyl value are important analytical characteristics of fats and oils. The iodine (I<sub>2</sub>) required saturating the fatty acids present in 100 grams of the oil... The iodine value (iodine number) and hydroxyl value are important analytical characteristics of fats and oils. The iodine (I<sub>2</sub>) required saturating the fatty acids present in 100 grams of the oil or fat. Iodine value is a measure of the total number of double bonds (-C=C-) present in fats and oils. Unsaturated compounds contain molecules with double and triple bonds which are very reactive towards iodine. The iodine value has been determined according to Hanus with iodine monobromide in glacial acetic acid, and then the amount of iodine remaining unreacted is determined by titration using sodium thiosulfate volumetric standard solution. The hydroxyl value is the amount of potassium hydroxide in milligrams that is equivalent to the hydroxyl amount of 1 gram of the sample (mg KOH/g sample). Poloxyl Stearyl Ether is a mixture of the monostearyl ethers of mixed polyethylene glycols. It may contain various amounts of free stearyl alcohol and some free polyethylene glycol. In this study, the iodine value and hydroxyl value have been determined by titration in polyoxyl stearyl ether. Iodine value 1.84 g of I<sub>2</sub> absorbed/100g sample, and hydroxyl value 162.65 mg KOH/g sample have been found in poloxyl stearyl ether. The iodine value and hydroxyl value results met the United States Pharmacopeia specifications for Polyoxyl Stearyl Ether. 展开更多
关键词 Iodine Value hydroxyl Value Hanus Method Polyoxyl Stearyl Ether
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Understanding the hydroxyl adsorption behavior at Pt electrode surface in high-temperature alkaline solutions
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作者 Bo Pan Biao Liu +3 位作者 Shaona Wang Yeqing Lv Hao Du Yi Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第2期173-179,共7页
Since the application in fuel cell,the electrochemical adsorption of hydroxyl has received considerable attention in recent years.While most research mainly focus on the room temperature,in this paper,the electrochemi... Since the application in fuel cell,the electrochemical adsorption of hydroxyl has received considerable attention in recent years.While most research mainly focus on the room temperature,in this paper,the electrochemical adsorption of hydroxyl in alkaline solution at high temperature was investigated.An unusual oxidation peak was observed at-0.27 V,suggesting new behavior of hydroxyl adsorption occurred.As is known two kinds of cation hydrated clusters exist in alkaline solution,(H_(2)O)_(x-1)M^(+)-H_(2)O-O_(ad)H and(H_(2)O)_xM^(+)-O_(ad)H.For K^(+)and Cs^(+),the cluster shows unstable structure due to the weak interaction between hydrated cation and OH^(-)especially at high temperature.However,For Li^(+),Na^(+)the cluster structure would be stable,as the interaction force between the hydrated cation and OH^(-)is so strong.It was revealed that the unusual oxidation peak has some relationship with the(H_(2)O)_(x-1)M^(+)-H_(2)O-O_(ad)H cluster(K^(+)and Cs^(+))absorbed at Pt electrode surface.When the temperature was raised,(H_(2)O)_(x-1)M^(+)-H_(2)O-and-O_(ad)H was disconnected,then the O_(ad)H absorbed at Pt surface got oxidated.Based on the SEM observation,it was showed the unusual electrochemical oxidation reaction would generate platinum oxides,blocking the reactive sites at Pt electrode surface,thus reducing the electrochemical reactivity of Pt electrode.Accordingly,parameters of alkaline concentration and temperature were systematically studied,it was found that increase temperature or alkaline concentration was in favor of the unusual oxidation reaction.This study provides more understanding of hydroxyl adsorption behavior at Pt electrode surface for the high temperature water solution environment. 展开更多
关键词 Alkaline solution hydroxyl adsorption Cationic species High temperature Cationic hydrated clusters
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Creation of cytochrome P450 catalysis depending on a non-natural cofactor for fatty acid hydroxylation
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作者 Qing Li Xiaojia Guo +4 位作者 Xueying Wang Junting Wang Li Wan Haizhao Xue Zongbao K.Zhao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期31-36,共6页
Cytochrome P450 enzymes catalyze diverse oxidative transformations at the expense of reduced nicotinamide adenine dinucleotide phosphate(NADPH),however,their applications remain limited largely because NADPH is cost-p... Cytochrome P450 enzymes catalyze diverse oxidative transformations at the expense of reduced nicotinamide adenine dinucleotide phosphate(NADPH),however,their applications remain limited largely because NADPH is cost-prohibitive for biocatalysis at scale yet tightly regulated in host cells.A highly challenging task for P450 catalysis has been to develop an alternative and biocompatible electrondonating system.Here we engineered P450 BM3 to favor reduced nicotinamide cytosine dinucleotide(NCDH)and created non-natural cofactor-dependent P450 catalysis.Two outstanding mutants were identified with over 640-fold NCDH preference improvement and good catalytic efficiencies of over15,000 M^(-1)s^(-1)for the oxidation of the fatty acid probe 12-(para-nitrophenoxy)-dodecanoate.Molecular docking analysis indicated that these mutants bear a compacted cofactor entrance.Upon fusing with an NCD-dependent formate dehydrogenase,fused proteins functioned as NCDH-specific P450catalysts by using formate as the electron donor.Importantly,these mutants and fusions catalyzed NCDH-dependent hydroxylation of fatty acids with similar chain length preference to those by natural P450 BM3 in the presence of NADPH and also similar regioselectivity for subterminal hydroxylation of lauric acid.As P450 BM3 and its variants are catalytically powerful to take diverse substrates and convey different reaction paths,our results offer an exciting opportunity to devise advanced cell factories that convey oxidative biocatalysis with an orthogonal reducing power supply system. 展开更多
关键词 Biocatalysis Cytochrome P450 Directed evolution Fatty acid hydroxylation Non-natural cofactor Synthetic biology
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黄铜矿粗选指标对水玻璃超声波改性的响应及其机理 被引量:2
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作者 张帅 赵鑫 +3 位作者 雷大士 王宇斌 张璐 田晓珍 《有色金属工程》 CAS 北大核心 2024年第1期92-99,共8页
为阐明黄铜矿粗选指标与水玻璃超声波改性的内在关系,以超声波预处理的水玻璃为调整剂,进行了黄铜矿实际矿物的浮选试验,并采用pH值、黏度及红外光谱等手段对超声波预处理水玻璃溶液及矿浆浊度进行了表征。结果表明,黄铜矿的粗选回收率... 为阐明黄铜矿粗选指标与水玻璃超声波改性的内在关系,以超声波预处理的水玻璃为调整剂,进行了黄铜矿实际矿物的浮选试验,并采用pH值、黏度及红外光谱等手段对超声波预处理水玻璃溶液及矿浆浊度进行了表征。结果表明,黄铜矿的粗选回收率对超声波改性的水玻璃较为敏感。铜的回收率在水玻璃预处理时间为15 min作用时的敏感性最强,为85.42%,与未改性水玻璃的回收率相比提高了9.19个百分点。超声波预处理可减小水玻璃溶液的pH值,并使其黏度降低0.36%,这有利于水玻璃在矿浆中的分散。此外,超声波预处理还可改变水玻璃溶液的中水分子的比例以及水玻璃官能团的组成,并使预处理后的水玻璃溶液中游离水羟基与H 2 SiO 3中的Si—OH的相对比例分别提高7.83个百分点和1.08个百分点。游离水组份的增加有利于改善黄铜矿的疏水性及浮选效果,水玻璃有效成分H 2 SiO 3中Si—OH的组份增加在一定程度上强化了对矿泥的分散作用,从而提高了粗选作业铜的回收率。研究对超声波技术在有色金属浮选领域的应用有一定参考意义。 展开更多
关键词 黄铜矿 超声波改性 水玻璃溶液 羟基比例 响应
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水液相下羟自由基与谷氨酸分子反应机理的量子化学研究 被引量:1
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作者 牛鹤丽 杨应 +5 位作者 徐岩 孙艳雨 郝成欣 王佐成 姜春旭 赵丽红 《复旦学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期143-154,共12页
采用密度泛函理论的M06-2X和MN15方法,结合自洽反应场理论的SMD模型方法,研究了水液相下羟自由基(OH)与谷氨酸分子(Glu)反应的机理。研究发现:Glu的损伤可通过OH抽取其不同位置的H原子、OH加成到羧基和去质子羧基C以及单电子从Glu分子... 采用密度泛函理论的M06-2X和MN15方法,结合自洽反应场理论的SMD模型方法,研究了水液相下羟自由基(OH)与谷氨酸分子(Glu)反应的机理。研究发现:Glu的损伤可通过OH抽取其不同位置的H原子、OH加成到羧基和去质子羧基C以及单电子从Glu分子向OH转移3个途径实现。势能面计算表明:OH加成到羧基和去质子羧基C的反应通道最具优势,反应无势垒;OH抽取质子化氨基H、α-H、β-H、γ-H和羧基H的最低能垒分别是28.7、17.6、8.0、18.3和29.0 kJ/mol;电子从Glu分子向OH转移为劣势通道,反应能垒是255.2 kJ/mol。结果表明,水液相下OH加成和抽H均可诱导Glu分子损伤,损伤的Glu绝大多数难以修复,Glu具有清除羟自由基的能力。 展开更多
关键词 谷氨酸 羟自由基 密度泛函理论 过渡态 电子转移 能垒 损伤
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端丙烯酸酯基聚丁二烯的合成与表征
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作者 莫洪昌 卢先明 +2 位作者 徐明辉 谭博军 刘宁 《化工新型材料》 CAS CSCD 北大核心 2024年第5期172-175,共4页
为了发展新型固化粘合剂,以端羟基聚丁二烯(HTPB)和丙烯酰氯为原料,经过酰化反应制备出端丙烯酸酯基聚丁二烯(ATPB),通过红外光谱、核磁共振氢谱和凝胶渗透色谱对ATPB的结构进行了表征,采用锥板黏度计研究了其黏度,DSC测定了其玻璃化转... 为了发展新型固化粘合剂,以端羟基聚丁二烯(HTPB)和丙烯酰氯为原料,经过酰化反应制备出端丙烯酸酯基聚丁二烯(ATPB),通过红外光谱、核磁共振氢谱和凝胶渗透色谱对ATPB的结构进行了表征,采用锥板黏度计研究了其黏度,DSC测定了其玻璃化转变温度,考察了ATPB与含能材料的相容性。结果表明,酰化反应后,HTPB的端羟基吸收峰完全消失,出现了丙烯酸酯基团的特征峰,聚丁二烯分子链未发生断裂,获得了目标化合物;ATPB的玻璃化转变温度为-83.61℃,25℃时黏度为10.10Pa·s;ATPB与高氯酸铵(AP)、黑索今(RDX)相容性好,预期在复合推进剂中具有良好的应用前景。 展开更多
关键词 有机化学 丙烯酸酯基团 端羟基聚丁二烯 丙烯酰氯 固化体系
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钒基催化剂催化苯羟基化制苯酚反应机理
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作者 李贵贤 李金莲 +3 位作者 邵婷娜 李晗旭 田涛 董鹏 《精细化工》 EI CAS CSCD 北大核心 2024年第2期257-268,329,共13页
苯羟基化制苯酚是C—H键向C—O键转化及富有挑战性的课题之一。该文论述了钒基催化剂催化苯羟基化制苯酚反应机理的研究进展。以钒活性中心为主线,着重从自由基、非自由基和双催化活性机理进行了详细介绍,同时分析了双催化活性中心催化... 苯羟基化制苯酚是C—H键向C—O键转化及富有挑战性的课题之一。该文论述了钒基催化剂催化苯羟基化制苯酚反应机理的研究进展。以钒活性中心为主线,着重从自由基、非自由基和双催化活性机理进行了详细介绍,同时分析了双催化活性中心催化剂高效催化的本质和重要性。提出此类催化体系及催化机理能够解决苯环上C—H键难活化和苯酚的深度氧化等问题,是经济与安全并存的苯酚合成方法,依托已有的催化反应机理,开发更稳定且高性能的催化剂,以促进烃类有机化合物资源利用的原始创新。 展开更多
关键词 苯酚 羟基化 反应机理 钒基催化剂
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羟基化氮化硼改性PLA纳米纤维膜的制备及性能研究
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作者 王丽 李金强 +3 位作者 房志敏 谭文萍 明津法 王健 《棉纺织技术》 CAS 2024年第8期1-7,共7页
为拓展生物基可降解PLA纳米纤维膜在空气过滤等医疗卫生领域的应用范围,通过机械剥离与功能化改性方法制备羟基化氮化硼(BNO)二维纳米片,并采用静电纺丝工艺制备羟基化氮化硼纳米片改性聚乳酸(PLA/BNO)纳米纤维膜。探讨BNO纳米片的引入... 为拓展生物基可降解PLA纳米纤维膜在空气过滤等医疗卫生领域的应用范围,通过机械剥离与功能化改性方法制备羟基化氮化硼(BNO)二维纳米片,并采用静电纺丝工艺制备羟基化氮化硼纳米片改性聚乳酸(PLA/BNO)纳米纤维膜。探讨BNO纳米片的引入对PLA纳米纤维膜的微观结构与形貌、导热性能、力学性能以及空气过滤性能的影响。结果表明:与纯PLA纳米纤维膜相比,PLA/BNO纳米纤维膜的拉伸力学性能以及导热性能显著提高。当纺丝液中BNO纳米片质量分数为0.7%时,风速为0.01 m/s时,PLA/BNO纳米纤维膜的过滤效率为99.97%,品质因子达到最大值0.262 Pa^(-1),阻力压降最小为31 Pa,PLA/BNO纳米纤维膜的拉伸断裂强度以及导热系数较纯PLA纳米纤维膜分别提高27.39%和26.62%。 展开更多
关键词 聚乳酸 羟基化氮化硼 静电纺丝 过滤性能 导热性 力学性能
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多金属掺杂尖晶石型催化剂制备及催化臭氧降解苯酚
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作者 刘艳芳 张妙雨 +6 位作者 刘文佳 杨梦鑫 孔兴华 任少勃 王崇璞 李欢欢 李贵霞 《安全与环境学报》 CAS CSCD 北大核心 2024年第10期4052-4061,共10页
采用水热合成法制备尖晶石型铁氧体,并对其M位掺杂多种金属离子以改性得到一系列催化剂,筛选后用于催化臭氧氧化降解苯酚。结果显示:与其他催化剂相比,Mn_(0.5)Co_(0.5)Fe_(2)O_(4)催化剂催化性能最佳,在苯酚质量浓度为30 mg/L,催化剂... 采用水热合成法制备尖晶石型铁氧体,并对其M位掺杂多种金属离子以改性得到一系列催化剂,筛选后用于催化臭氧氧化降解苯酚。结果显示:与其他催化剂相比,Mn_(0.5)Co_(0.5)Fe_(2)O_(4)催化剂催化性能最佳,在苯酚质量浓度为30 mg/L,催化剂投加质量浓度为1 g/L,臭氧质量浓度为6 mg/L,流速为1 L/min并反应75 min时,化学需氧量(Chemical Oxygen Demand,COD)和苯酚的去除率分别可以达到90.11%和89.36%,较相同条件下单独臭氧氧化对COD和苯酚的去除率分别提高了31.16百分点和30.51百分点。利用X射线衍射(X-ray Diffraction,XRD)、X射线光电子能谱(X-ray Photoelectron Spectroscopy,XPS)、电子顺磁共振(Electron Paramagnetic Resonance,EPR)等多种手段对该催化剂进行了表征,发现催化剂纯度较高,晶化程度好。此外,通过猝灭和自由基捕获试验表明体系中·OH和^(1)O_(2)参与了苯酚降解反应。催化剂循环试验表明,Mn_(0.5)Co_(0.5)Fe_(2)O_(4)催化剂具有优异的催化稳定性和重复利用性。 展开更多
关键词 环境工程学 催化臭氧氧化 苯酚 羟基自由基 单线态氧
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二氧化铅电极改性及电催化降解焦化废水中蒽
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作者 章丽萍 袁合霞 +4 位作者 安逸云 王晶 段梦楠 雷文波 王丽芳 《矿业科学学报》 CSCD 北大核心 2024年第2期286-294,共9页
为了研究电催化对焦化废水中污染物的降解效果,采用电沉积法制备了Ti/PbO_(2)、Ti/PANI/PbO_(2)和Ti/PANI/PbO_(2)-Ce三种电极,对电极进行扫描电镜和X射线衍射表征、电化学性能测试、产羟基自由基(·OH)能力测试和加速寿命测试。结... 为了研究电催化对焦化废水中污染物的降解效果,采用电沉积法制备了Ti/PbO_(2)、Ti/PANI/PbO_(2)和Ti/PANI/PbO_(2)-Ce三种电极,对电极进行扫描电镜和X射线衍射表征、电化学性能测试、产羟基自由基(·OH)能力测试和加速寿命测试。结果表明,经聚苯胺(PANI)和铈(Ce)改性的Ti/PANI/PbO_(2)-Ce电极具有更好的表面形貌和更高的催化活性,能产生更多的·OH,析氧电位为1.83 V,加速寿命时间为720 min。采用Ti/PANI/PbO_(2)-Ce电极降解焦化废水中的蒽,考察了主要因素对降解效果的影响,得到蒽的最佳降解条件为电压14 V,板间距1.0 cm,电解质浓度0.35 mol/L,反应时间120 min,pH值10。Ti/PANI/PbO_(2)-Ce电极显示了良好的电催化性能。 展开更多
关键词 电催化氧化 聚苯胺 羟基自由基 焦化废水
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Fe-PC-CNT中空纤维膜对磺胺甲噁唑的电芬顿降解研究
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作者 乔森 季子轩 《安全与环境学报》 CAS CSCD 北大核心 2024年第9期3637-3646,共10页
研究利用铁-多孔碳-碳纳米管(Ferrum-Porous Carbon-Carbon Nanotube,Fe-PC-CNT)中空纤维膜作为过滤中心和电化学阴极构建电芬顿体系,该体系能够将模拟废水中的溶解氧在膜表面还原成过氧化氢(H_(2)O_(2)),进而在Fe~(2+)的催化下产生羟... 研究利用铁-多孔碳-碳纳米管(Ferrum-Porous Carbon-Carbon Nanotube,Fe-PC-CNT)中空纤维膜作为过滤中心和电化学阴极构建电芬顿体系,该体系能够将模拟废水中的溶解氧在膜表面还原成过氧化氢(H_(2)O_(2)),进而在Fe~(2+)的催化下产生羟基自由基(·OH),以达到降解磺胺甲噁唑(Sulfamethoxazole,SMX)的目的。利用场发射扫描电子显微镜(Field Emission Scanning Electron Microscopy,FE-SEM)、X射线光电子能谱(X-ray Photoelectron Spectroscopy,XPS)对电芬顿膜形貌及元素价态进行分析,结果显示膜内部存在微孔结构,膜表面存在铁离子,利于H_(2)O_(2)的产生及活化。通过试验探究,发现在施加电压为-1.0 V(vs.SCE)、pH值为3、SMX初始质量浓度为600μg/L的条件下能够去除96.5%的SMX。根据猝灭试验和电子顺磁共振测试,得知·OH是反应中存在的主要活性物种。此外,Fe-PC-CNT中空纤维膜在4个循环后仍表现出良好的稳定性。研究可为去除水环境中的抗生素提供方案。 展开更多
关键词 环境工程学 电芬顿 羟基自由基 膜过滤 磺胺甲噁唑
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MTi-LDH(M=Zn,Ni)的制备及其对乙硫醇的吸附性能研究
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作者 崔洪珊 何杰 +3 位作者 王丽平 徐从波 张龙玉 李紫妍 《芜湖职业技术学院学报》 2024年第1期23-29,共7页
TiO_(2)是环境催化领域最常用、应用最广泛的催化剂之一,但其表面羟基常显酸性,限制了其在乙硫醇等酸性气体中的吸附性能。用Zn和Ni元素对其进行修饰,构建ZnTi-LDH、NiTi-LDH等钛基层状双金属氢氧化物,在对其结构特征进行表征的基础上,... TiO_(2)是环境催化领域最常用、应用最广泛的催化剂之一,但其表面羟基常显酸性,限制了其在乙硫醇等酸性气体中的吸附性能。用Zn和Ni元素对其进行修饰,构建ZnTi-LDH、NiTi-LDH等钛基层状双金属氢氧化物,在对其结构特征进行表征的基础上,选择甲烷气中的乙硫醇为研究对象,研究二元的钛基层状双金属氢氧化物对甲烷气中乙硫醇的吸附作用,及层状化合物的层板和表面酸碱性等对乙硫醇吸附性能的影响。研究结果表明,采用固定床反应器动态吸附乙硫醇,发现ZnTi-LDH的穿透硫容为8.04 mg·g^(-1),而NiTi-LDH的吸附性能要优于ZnTi-LDH,其穿透硫容为13.79 mg·g^(-1)。该催化剂优异的吸附脱硫活性使其在工业应用上具有一定的前景。 展开更多
关键词 ZnTi-LDH NiTi-LDH 羟基 乙硫醇 吸附脱硫
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出芽短梗霉LHS-m022黑色素葡聚糖的发酵影响因素和生物活性
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作者 栾兴社 栾欣阳 张长铠 《北京大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第5期799-806,共8页
为探索出芽短梗霉LHS-m022黑色素多糖的发酵影响因素和生物活性,采用菌种发酵、分离提取及生物检测方法,对发酵液性质、产物收率、生物转化率及生物活性进行测定分析。结果表明,LHS-m022黑色素多糖发酵的最佳碳、氮源分别是蔗糖和胰酪... 为探索出芽短梗霉LHS-m022黑色素多糖的发酵影响因素和生物活性,采用菌种发酵、分离提取及生物检测方法,对发酵液性质、产物收率、生物转化率及生物活性进行测定分析。结果表明,LHS-m022黑色素多糖发酵的最佳碳、氮源分别是蔗糖和胰酪蛋白胨,蔗糖最佳浓度为60 g/L;发酵培养基中诱导剂L-多巴的最适添加量为2.0 g/L,发酵液黑变活性和生物转化率分别是2.481和71.93%;细胞通透剂鼠李糖脂的最适添加量是0.021μL/L,发酵液黑变活性和生物转化率分别高达2.794和73.9%。全波长扫描、FTIR与HPLC分析表明,WAI为黑色素,PsB为黑色素葡聚糖结构。研究结果揭示,粗黑色素葡聚糖样品经121℃以上高温处理,仍然得到95.37%的絮凝率。采用1.50和2.00 g/L的样品浓度进行检测,分别得到99.55%的羟自由基清除活性和99.00%的抗氧化活性。 展开更多
关键词 出芽短梗霉LHS-m022 黑色素葡聚糖 黑变活性 生物转化率 抗氧化活性 羟自由基清除活性
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掺杂BN-OH纳米片的P/PEG@BN-OH同轴纳米纤维的制备及其热性能
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作者 石海峰 罗建文 《天津工业大学学报》 CAS 北大核心 2024年第2期1-9,共9页
为制备高效稳定的相变储热材料,采用同轴静电纺丝技术制备了以聚丙烯腈(PAN)为鞘、聚乙二醇(PEG)与羟基化氮化硼纳米片(BN-OH)为芯的同轴纳米纤维(P/PEG@x BN-OH),并分别通过场发射扫描电子显微镜、透射电子显微镜、差示扫描量热仪、红... 为制备高效稳定的相变储热材料,采用同轴静电纺丝技术制备了以聚丙烯腈(PAN)为鞘、聚乙二醇(PEG)与羟基化氮化硼纳米片(BN-OH)为芯的同轴纳米纤维(P/PEG@x BN-OH),并分别通过场发射扫描电子显微镜、透射电子显微镜、差示扫描量热仪、红外热成像仪等手段分析了掺杂不同质量BN-OH纳米片对纤维形貌、热性能、循环稳定性、热能效率及热导率的影响。结果表明:纤维形成了稳定且连续的鞘-芯同轴结构,平均直径介于279~335 nm,而且PEG和BN-OH被包裹在PAN纤维内部,内径大小范围为107~188 nm;P/PEG@x BN-OH纳米纤维显示了优异的相变储热焓值(75~78 J/g)和热稳定性,经100次热循环后PEG无相变渗漏现象;掺杂质量分数为10.0%的BN-OH纳米片可将纤维的热导率提高95%,而且其相变储热和释放率分别提高了67%和154%。 展开更多
关键词 同轴纤维 相变材料 羟基化氮化硼 热导率 相变储热
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聚氨酯改性有机硅表面活性剂的制备与性能研究
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作者 李艳平 《炼油与化工》 CAS 2024年第5期49-51,共3页
利用聚氨酯的特性对有机硅进行改性,通过改变高键能和低表面能的Si-O键,使其具有良好的氧化稳定性和耐水性。文中提出聚氨酯改性有机硅高分子表面活性剂的制备与性能研究。准备制备原料和仪器后,将20.0%、25.0%、30.0%体积的端羟烃基聚... 利用聚氨酯的特性对有机硅进行改性,通过改变高键能和低表面能的Si-O键,使其具有良好的氧化稳定性和耐水性。文中提出聚氨酯改性有机硅高分子表面活性剂的制备与性能研究。准备制备原料和仪器后,将20.0%、25.0%、30.0%体积的端羟烃基聚硅氧烷3667分散在70.0%体积的聚乙二醇(PEG2000)中,同时加入去离子水进行定量,得到聚氨酯改性的有机硅表面活性剂。在性能测试阶段,分别对目标产物的红外光谱分布情况以及表面张力情况进行测试,对端羟烃基聚硅氧烷3667浓度与表面活性剂性能之间的关系进行了综合分析。 展开更多
关键词 聚氨酯 改性有机硅 高分子表面活性剂 端羟烃基聚硅氧烷3667 红外光谱分布
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