等离子体处理催化剂应用于大气污染控制研究进展

利用等离子体处理催化剂是目前比较有吸引力和发展前景的技术.介绍了等离子体处理催化剂应用于大气污染控制方面的研究进展,分别讨论了等离子体的处理对催化剂比表面积和孔径、分散性、稳定性、活性、其他结构等的影响,以及等离子体处理条件对催化剂性能的影响,探讨了等离子体技术在催化剂制备方面的应用前景和发展方向.     

低温等离子体在催化剂制备及协同催化反应中的研究进展

等离子体化学作为一个全新的研究领域,引起了越来越多学者的兴趣和重视。作者综述了目前等离子体在催化剂制备及协同催化反应中的应用,在此基础上,展望了等离子体化学未来的研究趋势。     

等离子体制备负载型金属纳米催化剂的研究进展

等离子体主要是由离子、电子等粒子组成的呈电中性且高度离子化的气体。可在室温条件下,利用等离子体中的高能粒子对化学物质进行还原,避免高温条件下粒子发生团聚,易得到粒径小、分散性好的纳米颗粒。对近年来等离子体技术制备负载型金属纳米催化剂及其催化性能进行了综述。     

低温氢气等离子体的应用

等离子体技术越来越受到人们的重视。氢气由于自身性质的特殊性,其等离子体具有其他气体等离子体所没有的特性,如氢气等离子体特殊的还原性能。对低温氢气等离子体的用途作了概述。     

等离子体技术在催化剂制备中的应用

等离子体作为一种新技术,在诸多领域有着广阔的应用.综述了等离子体技术在催化剂制备方面的应用,介绍了等离子体技术制备催化剂的方法、装置以及利用等离子体技术制备和再生回收金属、金属氧化物催化剂的研究进展,分析展示了等离子体技术在催化剂制备方面的应用前景.     

提高煤直接液化催化剂活性的研究进展及展望

为制备高效的煤直接液化催化剂,综述了提高煤直接液化催化剂活性的方法,分析了各方法对煤直接液化催化剂性能影响的作用原理,指出了煤直接液化催化剂研究中各方法的关键点和难点,各方法之间并非相互孤立,应有机组合以提高催化剂的活性。针对目前煤直接液化催化剂存在的问题提出了发展展望。煤直接液化催化剂活性提升的方法主要有提高催化剂前驱体的分散度,提高活性相的抗聚结性能和利用多元金属/非金属的复合/协同效应,后续研究应加强煤中灰组成对催化剂性能的影响,深入研究非金属元素对催化剂加氢和抑焦性能的影响,探索多种协同复合的催化剂制备系统,针对特定煤种研制专用高效直接液化催化剂。     

非热等离子体催化转化C1分子及其催化剂研究进展

非热等离子体催化具有反应条件温和、启动快和反应器结构紧凑等特点,在C₁分子催化转化领域（如CO₂加氢、甲烷活化、水煤气变换反应和甲醇重整制氢）有着广阔的应用前景。具体来说,等离子体特有的高能电子可在气相中快速活化稳定性极强的C₁分子并生成活性物质,接着与催化剂结合发生表面化学反应,从而实现常温常压下C₁分子的高效转化。然而,等离子体与催化剂之间的协同作用机制以及催化机理极为复杂,仍有待进一步研究。本综述简单介绍了非热等离子体催化转化C₁分子的近期研究进展,重点探讨了适用于非热等离子 体的催化剂研究以及催化机理的高级原位表征。最后,提出了非热等离子体催化转化C₁分子的未来发展方向：①设计并构筑适用于非热等离子体催化的高效催化剂,并研究其构效关系;②发展高级原位表征技术,揭示活性物质的作用机理以及催化机理;③设计并构建高效的等离子体催化反应器,并建立反应器的理论模型和数值模拟方法,科学指导等离子体反应器的设计、优化和放大。     

冷等离子体在甲烷转化中的研究进展

文章综述了近几年国内外利用冷等离子体活化转化甲烷、与催化剂协同作于甲烷转化以及改性甲烷转化用催化剂中的研究进展。等离子体技术作为一种新兴技术为甲烷转化注入了新的力量,对天然气的有效利用、减少温室气体的排放和绿色化工有着重要的意义。     

非平衡等离子体水处理技术研究进展

回顾了高压脉冲电源的发展概况,对现行研究中使用的非平衡等离子体水处理反应器进行了分类,系统总结了液相、气相和气液两相放电反应器的研究现状,指出了待改进之处和发展趋势。归纳了脉冲放电过程中催化剂的使用状况,分析了催化剂在脉冲放电过程中的作用,指出了不同催化剂在使用过程中存在的问题及进一步研究的方向。     

低温等离子体协同铜铈催化剂脱除甲苯

以挥发性有机化合物（VOCs）中的代表物质甲苯作为脱除对象,采用柠檬酸水热法制得铜铈催化剂,考察了低温等离子体协同不同摩尔比铜铈催化剂脱除甲苯的性能。研究发现铜铈复合型金属催化剂可以大幅度提升低温等离子体对甲苯的脱除效率,降低初始浓度、气体流速和升高电压可以提高甲苯脱除效率。同时利用N₂吸附-脱附（BET）、X射线衍射（XRD）、X射线光电子能谱（XPS）、程序升温还原（H₂-TPR）、红外光谱（FTIR）等手段对催化剂进行表征,发现催化剂活性组分分布较均匀,铜铈复合型金属催化剂表面氧空位、吸附态氧含量高于单金属氧化物催化剂,这有利于催化剂活性氧的释放。铜铈之间存在着协同作用,铜铈之间的氧化还原循环有利于甲苯的氧化。     

The effect of water on the reduction of nickel/alumina catalysts

The crucial role of water in the reduction of calcined nickel/alumina catalysts is demonstrated. A fraction of nickel oxide in the catalysts is reduced as NiO powder in the absence of water vapour, and as a nickel aluminate in the presence of water. A much higher dispersion of nickel is attained when the reduction is carried out at low concentration of water vapour.     

Fundamental study on the NOx direct decomposition catalysts

We are developing direct decomposition catalysts to decompose the NO_x involved in high temperature exhaust gases to N₂ and O₂ without any reductants such as urea and plan to bring this technology into practice in the 21st century. We expect to create very simple deNO_x systems using direct decomposition catalysts applicable to a wide range of fields (co-generation, boilers, automobiles and so on) after overcoming the technical difficulties. Perovskite catalyst and zeolite catalyst are the most promising materials for direct decomposition catalysts. This study focuses on seeking and designing novel NO_x direct decomposition catalysts having high activities through theoretical studies using computational chemistry and experimental studies using surface-science techniques.     

环己基苯的合成及其催化剂研究进展

环己基苯经过氧化反应可生产苯酚和环己酮,还可以用作锂离子电池电解液的添加剂,也可用作柴油的十六烷值调和组分,是一种高附加值、有市场潜力的精细化学品。本文介绍了国内外通过苯与环己烯烷基化合成环己基苯及所用催化剂的研究进展,总结了苯加氢烷基化反应机理和反应路径的研究成果,包括加氢烷基化活性的来源、中间产物和碳正离子中间体的推断以及各反应产物的形成。通过对加氢烷基化机理的认识,回顾了加氢烷基化催化剂的设计思路和发展历程。最后指出可开发用于苯与环己烯烷基化的B酸型、B-L酸型以及固载化离子液体等新型催化剂。提出可借助最新的碳正离子研究手段对加氢烷基化机理进行补充完善,并认为可利用多级孔沸石作为加氢烷基化催化剂的酸性载体。     

NO + H2 reaction on Pt-Ru/SiO2 catalysts: correlation between nanostructure and catalytic activity and selectivity

Nitric oxide reduction by hydrogen has been studied on Pt-Ru/SiO₂ catalysts of various Pt/Ru atomic compositions in the temperature range 298–673 K. Physical characterization showed the presence of bimetallic particles which tend to be Pt-rich. The overall activity of the bimetallic catalysts suggests a dilution of the active component (Pt) in the range 373–523 K. The addition of Ru results in a general improvement of the N₂ selectivity and significant modifications in the product distribution are observed as a function of the catalyst composition. A bimetallic particle model is proposed in which various types of surfaces are exposed including those with pure Pt atoms and/or Pt-Ru mixture. This model allows to explain the overall activity and selectivity in the whole series of catalysts.     

A cooperative effect between support and the heterogenised metalloporphyrins on electrocatalytic oxygen reduction

A new general method to heterogenise porphyrins and different metalloporphyrins (Co, Fe) on silica, mesoporous MCM-41 and delaminated zeolites ITQ-2 and ITQ-6 yields stable materials, which act as active catalysts for the electrochemical oxygen reduction, without catalyst desorption from the electrode.     

Liquid discharge plasma for fast biomass liquefaction at mild conditions: The effects of homogeneous catalysts

Non-thermal plasma exhibits unique advantages in biomass conversion for the sustainable production of higher-value energy carriers. Different homogeneous catalysts are usually required for plasma-enabled biomass liquefaction to achieve time-and energy-efficient conversions. However, the effects of such catalysts on the plasma-assisted liquefaction process and of the plasma on those catalysts have not been thoroughly studied. In this study, an electrical discharge plasma is employed to promote the direct liquefaction of sawdust in a mixture of polyethylene glycol 200 and glycerol. Three commonly used chemicals, sulfuric acid, nitric acid and sodium p-toluene sulfate, were selected as catalysts. The effects of the type of catalyst and concentration on the liquefaction yield were examined; further, the roles of the catalysts in the plasma liquefaction process have been discussed. The results showed that the liquefaction yield attains a value of 90% within 5 min when 1% sulfuric acid was employed as the catalyst. Compared with the other catalysts, sulfuric acid presents the highest efficiency for the liquefaction of sawdust. It was observed that hydrogen ions from the catalyst were primarily responsible for the significant thermal effects on the liquefaction system and the generation of large quantities of active species; these effects directly contributed to a higher efficacy of the plasma-enabled liquefaction process.     

Application of plasma spraying in the preparation of metal-supported catalysts

Catalysts supported on metals are widely used today, but room still remains for further improvement of catalyst characteristics. The subject of this paper is the application of a plasma spray for the deposition of alumina coatings on metal substrates of different geometry (plates, foams) for subsequent synthesis of catalysts. The alumina layer sprayed successfully solves two different problems: (i) it serves as a washcoat on which a catalyst is synthesized, and (ii) it protects the metal surface from oxidation at high temperatures.     

釜式淤浆法生产高密度聚乙烯工艺及催化剂研究进展

介绍了用于生产高密度聚乙烯的三井油化公司CX工艺及Basell公司Hostalen工艺;总结了於浆工艺聚乙烯催化剂(三井油化PZ、RZ催化剂,北京化工研究院的BCH、BCE催化剂,辽宁向阳科化集团的XYH催化剂,Basell公司的TH催化剂、铬系催化剂,辽阳石化的JM-1催化剂)的特点;对各个催化剂的优缺点进行了对比;对我国淤浆工艺高密度聚乙烯催化剂的研究和应用提出了建议。     

壳聚糖负载催化剂的研究进展

天然高分子壳聚糖是一天然碱性多糖,它对金属离子具有良好的螫合能力,其配合物可作为氢化、氧化偶合、开环聚合、烯类单体聚合、酯化、醚化等反应的催化剂和引发剂。主要对壳聚糖负载催化剂的研究进展进行了综述。