六氯苯的水相催化脱氯研究

一种新型双负载双金属催化剂PVP-PdCl2-MnXm/MontK10-PEG400的制备,是把起相转移作用的聚乙二醇(PEG),键合到蒙脱土上,将聚乙烯吡咯烷酮(PVP)络合双金属后再负载其上.以甲酸钠为氢转移试剂,用此催化剂在水相中对六氯苯进行催化脱氯.当反应温度为90℃,反应时间为36小时,且Pd和金属M的摩尔比为4:1时,其转化率为100%.该催化剂不但易于制备,而且便于分离.     

负载型Pd基双金属催化剂的设计及其在环境领域的应用（英文）

负载型双金属催化剂在很多催化反应中都有着十分重要的意义,包括选择性氧化、加氢/氢解、重整、生物质转化等反应。这一类催化剂的活性、选择性和稳定性取决于颗粒尺寸、组成和形貌等结构特性。针对Pd基负载型双金属催化剂体系,本文讨论了其结构特性,并探讨了不同合成方法对结构性质的调控机制。同时,本文阐述了Pd基催化剂在环境催化反应中的应用,包括CO氧化、烃类氧化、加氢脱氯和NO_x分解等反应。尽管在这些领域的研究取得了一定的进展,然而还需要更先进的催化技术来应对一些重大的挑战,如环境修复等。最近,在材料、光谱、显微、催化化学以及工程领域的研究人员的共同努力下,通过先进表征方法、机理研究手段的采用以及构效关系的研究,针对双金属催化剂设计的研究取得了一些新的进展。本篇综述旨在激励相关领域科学家设计合理的新型催化剂体系,以用于未来的绿色及可持续发展。     

对氯硝基苯加氢反应的高效催化剂研究

采用浸渍法制备了负载于活性炭的Ru-Pd双金属催化剂,研究了其催化对氯硝基苯加氢反应的性能,考察了催化剂的活性组成、反应温度、催化剂用量、H2压力等对加氢反应的影响.结果表明,在优化反应的条件下,对氯硝基苯的转化率可达到99.0%以上,生成的对氯苯胺选择性达到98.4%;催化剂循环使用5次后,催化剂的活性和选择性没有明显的下降.     

Cu/MMT催化剂的制备及催化性能

以CuC12和MMT(蒙脱土)为原料,采用离子交换法制备得到的Cu/MMT(蒙脱土)催化剂.将该催化剂用于咪唑与溴苯、咪唑与氯苯的反应.结果表明:咪唑与溴苯在该催化剂的作用下反应生成苯咪唑,而产率需要在以后更进一步的试验中得出;氯苯与咪唑在该条件下不反应,条件的进一步优化有可能使他们发生反应,这需要在今后的实验中验证.     

一种催化氢转移脱羰基化合物α-氯原子的方法

开发了一种催化氢转移脱羰基α-氯原子的方法。该方法以甲酸铵做氢供体,Pd/C为催化剂,室温条件,质子性溶剂。其最大优点为条件温和,后处理简便,反应时间短,收率高。     

一种新型脱卤催化剂的制备及红外光谱分析

一种新型双负载双金属催化剂PVP－PdCl2-SnCl4/MontK10-PECG400,用于催化难溶于水的芳香卤化物水相脱卤，在无须加入任何有机溶剂情况下，对芳香氯化物呈现出高的脱卤活性和选择性，并具有良好的重复使用性能，通过IR测定探讨了催化剂各组分在催化脱卤中的作用。     

硅藻土负载双金属类芬顿催化剂降解对氯苯酚的研究

利用硅藻土基负载Fe^3+/Mn^2+双金属催化剂对对氯苯酚溶液进行氧化降解,以TOC值考察其降解效果,研究了不同初始pH值、催化剂用量和H 2O 2投加量条件下,对对氯苯酚降解效果的影响。     

二氧化钛负载磷钨钒杂多酸的制备及其催化氧化脱硫性能研究

采用酸化-乙醚萃取法制备了Keggin结构的磷钨钒杂多酸,并分别采用浸渍法、溶胶-凝胶法制备了二氧化钛负载型杂多酸催化剂,采用紫外和红外光谱对催化剂进行表征.以H2 O2为氧化剂,以二苯并噻吩(DBT)的正辛烷溶液为模型柴油,对其氧化脱硫反应进行了研究,考察了催化剂对模拟油品中二苯并噻吩(DBT)的氧化脱硫反应性能研究,考察了不同制备方法、不同负载量对催化剂脱硫效率的影响.结果表明,溶胶凝胶法制备的负载型催化剂明显优于浸渍法制备的催化剂,在反应温度50℃,反应时间为4小时,n(H2 O2)/n(s)=4:1的优化条件下,DBT转化率达到89％.催化剂通过简单过滤法可分离回收,重复使用5次后DBT转化率为83％.     

新型MgO限域NiCo合金碳基催化剂用于苯胺与脂肪醇的N-烷基化反应（英文）

寻找一种成本效益高且可扩展的策略来制备高效的合金催化剂,用于N-烷基化反应仍然是一个挑战。通过自模板化策略,采用Ni-Co-Mg三金属MOFs(命名为Ni-Co-Mg@H₂dhbdc)作为前驱体,一步热解合成了香蕉状形貌固溶体限域NiCo合金的碳基新型纳米催化剂(命名为NiCo/MgO-C)。将此催化剂应用于苯胺与脂肪醇的N-烷基化反应,由于其独特的结构(如NiCo纳米颗粒的小尺寸,电子密度的增强传输)和NiCo合金特性,表现出卓越的性能,与双金属MOFs衍生催化剂(如Ni/MgO-C和Co/MgO-C)相比更优越。在热解过程中,发现Ni-Co-Mg@H₂dhbdc前体能够提高NiO-MgO或CoO-MgO固溶体中NiO或CoO物种的还原程度。因此,这种Ni-Co-Mg@H₂dhbdc MOFs模板化的策略是一种简单且可控的方法,用于合成负载型固溶体纳米合金催化剂应用于多相催化反应。     

TPD技术测定脱附活化能的估算模型

基于本征脱附动力学，本文建立对应于程序升温脱附（TPD）实验的脱附活化能估算模型，用化学改性的方法制备了Ag^ -活性炭，Cu^2 －活性炭，Fe^3 -活性炭，活性炭，Ba^2 -活性炭和Ca^2 -活性炭，利用TPD技术测定了正己醇在自制的六种活性炭上的脱附活化能，结果表明，正己醇在Ag^ -活性炭，Cu^2 -活性炭和Fe^3 －活性炭上的脱附活化能高于其在活性炭上的脱附活化能，而它在Ca^2 -活性炭和Ba^2 -活性炭上的脱附活化能低于它在活性炭上的脱附活化能。     

Kinetics of 2,4-dichlorophenol dechlorination by Pd-Fe bimetallic nanoparticles in the presence of humic acid

The remediation of groundwater which contains chlorinated organic compounds （COCs） by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dichlorophenol （2,4-DCP） by Pd-Fe bimetallic nanoparticles in the presence of humic acid （HA） to investigate the feasibility of using Pd-Fe for the in situ remediation of contaminated groundwater. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Pd-Fe nanoparticles. The rate constant k values of 2,4-DCP dechlorination were 0.017, 0.013, 0.009, 0.006 and 0.004 min^-1 for HA concentrations of 0, 5, 10, 15 and 20 mg/L, respectively. The relationship between HA dosage and k values can be described as a linear model.     

Novel Pt–Ni Bimetallic Catalysts Pt(Ni)–LaFeO3/SiO2 via Lattice Atomic-Confined Reduction for Highly Efficient Isobutane Dehydrogenation

In this study, a series of novel Pt-Ni bimetallic catalysts supported on LaFeO_3/SiO_2 with different amounts of Ni were prepared by the lattice atomic-confined reduction of LaFe_(1-x)(Ni, Pt)_xO_3/SiO_2 perovskite precursors and applied in isobutane dehydrogenation to isobutene reaction. The catalysts were characterized by X-ray diffraction, H_2-temperature-programmed reduction, Brunauer-Emmett-Teller analysis, transmission electron microscopy, energy dispersive X-ray, CO chemisorption, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The as-synthesized Pt-Ni bimetallic catalysts possessed smaller most probable particle size with tunable Pt-Ni interaction, depending on the Ni content. The catalyst with Ni content of 3.0 wt% showed excellent activity and stability(the isobutane conversion and isobutene selectivity remained at about 38% and 92%, respectively, after 310 min) for the isobutane dehydrogenation reaction. It also provided approximately six times turnover frequency of the catalyst without Ni. The excellent activity and stability of the 3.0 wt% Ni-containing catalyst can be attributed to its small metal nanoparticles with high dispersion and suitable Pt-Ni interaction. Moreover, the Pt(Ni)-LaFeO_3/SiO_2 catalyst with Ni content of 3.0 wt% had been run for more than 35 h without obvious loss of activity,indicating its long-term stability, and the decrease in the Pt-Ni interaction that accompanied the formation of the FeNi alloy phase was thought to be responsible for the slight decrease in activity.     

CdTe量子点荧光猝灭法对银离子和钙离子的测定

以CdTe量子点为荧光探针,基于荧光猝灭法对Ag（Ⅰ）和Ca（Ⅱ）进行了定量检测.考察了缓冲液的浓度、缓冲液pH值、反应时间等多种因素的影响.结果表明：（1）在浓度为10～20 mmol/L、pH值为7～8的磷酸二氢钠-磷酸氢二钠缓冲液中,Ag＋与量子点反应时间为20 min时,量子点荧光衰减程度（ΔF）与Ag＋浓度呈...     

Rapid dechlorination of chlorinated organic compounds by nickel/iron bimetallic system in water

Detoxification of chlorinated organic compounds via reaction with nickel/iron powder was implemented in aqueous solution. Compared to iron, nickel/iron bimetallic powder had higher hydrodechlorination activities for both atrazine (ATR) and p-chlorophenol (pCP); nickel/iron (2.96%, w/w) was shown to have the largest specific surface area and the optimum proportion for the dechlorination of both ATR and pCP. Electrochemical measurements showed that the adsorbed hydrogen atom on the nickel must have been the dominant reductive agent for the dechlorination of both ATR andpCP in this system.     

稀土元素镧(La~(3+))对绿豆下胚轴不定根形成的促进作用

稀土元素(La~(3+))在10~(-8)～10~(-5)mol/L浓度范围内,对绿豆下胚轴切段不定根形成(ARF)有促进作用。10~(-5)mol/LLa3~+与10~(-4)mol/LIBA混合处理时的生根数比用IBA处理的增加20％,即表现出协同效应,La~(3+)在不定根形成中的0～24h内处理时促进作用较大。这说明在ARF的诱导期和起始早期外施适当浓度的La~(3+)有利于根原基形成,并促进不定根形成。     

Designing Pd-based supported bimetallic catalysts for environmental applications

Supported bimetallic nanoparticulate catalysts are an important class of heterogeneous catalysts for many reactions including selective oxidation, hydrogenation/hydrogenolysis, reforming, biomass conversion reactions, and many more. The activity, selectivity, and stability of these catalysts depend on their structural features including particle size, composition, and morphology. In this review, we present important structural features relevant to supported bimetallic catalysts focusing on Pd-based bimetallic systems and recently reported strategies to control them through different synthesis methodologies. Further, we focus on a few reactions that are relevant to environmental catalysis, i.e. CO oxidation, hydrocarbon oxidation, hydrodechlorination, and NO _x decomposition, where Pd-based catalysts are often used successfully. In spite of much progress in these areas, still there is a need for more advanced catalytic technologies to address the grand challenges like environmental remediation. Some of the recent advances in the design of bimetallic catalysts were made because of the combined efforts of material scientists, spectroscopists, microscopists, catalysis chemists, and engineers through state-of-the-art characterization methodologies, mechanistic investigations, and structure-activity correlations. This review is aimed at inspiring scientists to rationally design catalysts for a green and sustainable future.     

苯并呋咱-N-氧化物及其衍生物合成工艺研究概况

苯并呋咱-N-氧化物及其衍生物的合成研究取得了很大进展,特别是采用次氯酸钠氧化邻硝基苯胺的合成方法和生产工艺呈现出许多不同的特点.这类合成以邻硝基苯胺一类化合物为原料,在碱金属氢氧化物催化作用下,用次氯酸钠氧化合成得到苯并呋咱-N-氧化物(BFO)或其衍生物.合成工艺研究多致力于降低原材料成本、提高生产的安全性、减少对生产环境的污染以及解决三废问题,同时使合成条件更加缓和,生产工艺更趋于合理,特别是在减少溶剂副反应,降低溶剂消耗等方面,各种工艺表现出不同特点.其中包括以乙醇、甲醇为溶剂的方法、甲苯或苯等为溶剂的相转移催化方法,直到以水、表面活性剂聚乙二醇等为反应介质合成BFO的方法.     

无机高分子混凝剂聚硅硫酸盐的制备

无机高分子絮凝剂是城市用水和工业废水处理的有效药剂。在研究聚合硫酸铁(PFS)合成工艺的基础上,设计出一套合成无机高分子混凝剂聚硅硫酸铁(PSPFS)和聚硅硫酸铝铁(PSAFS)的方法。采用正交试验法,通过模拟浊水的混凝试验,确定Fe/Si摩尔比、Na2SiO3.9H2O溶液聚合时间、反应时间、反应温度和Al/Si摩尔比等最佳参数。     

化学镀制备核-壳结构铜-银双金属粉的研究进展

本文主要介绍了化学镀法制备铜-银双金属粉过程中的预处理工艺、制备方法、存在的不足以及未来发展趋势.