汽车尾气净化催化剂发展方向

汽车尾气净化催化剂是控制汽车尾气排放，减少污染的最有效手段。按照我国总体规划，到2010年我国汽车尾气排放控制与国际接轨，达到国际水平。这为开发稀土汽车尾气净化催化剂材料，提供了很大的发展空间。     

汽车尾气净化催化剂

我国于1983年制定了汽车尾气排放标准和测量方法，国家质量技术监督局实行的汽车尾气排放标准与欧美国家标准对照数据见表1。     

稀土与汽车尾气净化

面临日趋严格的汽车尾气排放标准，采取各种净化手段治理和控制汽车尾气中有害物质的排放，已成为全球性环境治理研究的重要课题，受到世人的关注。稀土元素由于其特殊的电子结构，因而具有独特的功能，在汽车尾气净化中发挥着重要的作用，本文对稀土在汽车尾气净化几个方面的应用进行了综述。     

我国汽车尾气净化催化剂的研究现状

概述了我国汽车尾气净化催化剂的研究进展,对纳米稀土催化剂、不同助剂及活性组分负载量对催化剂性能的影响进行了详细阐述,指出我国汽车尾气净化催化剂的开发方向是含少量金属的稀土基催化剂.     

汽车尾气净化催化剂研究述评

综述了汽车尾气净化催化剂的研究与进展，其中主要介绍了稀土元素在催化剂中的应用。     

汽车尾气净化催化剂的研究

为了迎接越来越严格的汽车尾气排放标准的挑战，催化剂科研工作者必须与产业界合作，着重解决该领域扣关键技术，开发新型汽车尾气净沦稀土催化剂，以取代贵金属催化剂，并提高催化剂使用性能。     

汽车尾气净化催化剂及载体的研究进展

汽车尾气是大气污染的主要来源之一,汽车尾气净化器催化是控制汽车污染的重要手段。因此本文综述了汽车尾气净化催化剂及其载体的研究进展,包括催化剂及其载体的分类及研究进展。并对金属型催化剂及稀土复合型催化剂进行了优缺点的比较,提出了汽车尾气净化催化剂的研究发展方向。     

汽车尾气净化催化剂的研究及发展

汽车排放的尾气中含有大量的NOX、HC及CO,对人体危害很大,而高效汽车尾气净化催化剂是实现车外净化、解决这一问题的关键。国外发达国家已广泛使用三效催化剂。综述了汽车尾气净化催化剂的研究与进展,主要介绍了稀土元素在催化剂中的应用。     

汽车尾气净化催化剂

综述了国内外汽车尾气净化催化剂发展过程,分析了不同情况下催化剂对汽车尾气的转化情况,展示了汽车尾气催化剂的发展前景。     

汽车尾气净化催化剂研究概况

陈述了汽车尾气净化催化剂的研究概况，讨论了其净化机理，展望了其发展前景。     

汽车三效催化剂失活研究的进展

随着对汽车三效催化剂耐久性能要求的日益提高,因而对催化剂抗老化性能提出了更高的挑战,本文主要介绍了汽车三效催化剂失活的主要类型,包括:机械失活、化学失活及热失活。阐明了目前汽车三效催化剂所面临的主要的失活问题就是涂层基体γ-Al2O3烧结和贵金属的老化,同时论述了目前对γ-Al2O3和贵金属的主要改性方法,指出开发新型的耐高温稳定的涂层材料是目前所要研究的重点。     

汽车用催化剂技术--治理尾气污染的重要手段

催化技术是治理机动车排放污染的重要手段之一,车用催化剂已经和正在被广泛应用。本文对国内外３０年来车用催化剂研究作了综述。     

车用催化剂的评价及试验装置设计

评述了车用催化剂评价体系和催化剂台架活性评价实验方法,提出了用于车用催化剂性能评价的台架评价试验装置的设计方案。     

Nitric Oxide Catalysis in Automotive Exhaust Systems

This review covers the literature through 1991 on nitric oxide catalysis as applied to automobile exhaust systems. Attention is given to the threeway catalyst system which simultaneously promotes the reduction of nitrogen oxides and the oxidation of carbon monoxide and hydrocarbons. These systems have been used on most passenger cars in the United States since 1982. Prior to 1980, emission control catalysts were oxidation catalysts, and reduction in exhaust nitric oxide was achieved using engine modifications (i.e., exhaust gas recirculation). This review focuses on catalytic control of NO, for gasoline-fueled vehicles (not diesels and alternate fuels) and primarily on developments reported since 1982. The term NO, refers to both NO and NOz. The reader is referred to an earlier publication by the author for a general review of automobile catalytic converters [1] and to a review by Egelhoff [2] on the nitric oxide literature through 1980. The recent literature on NO, reduction in lean exhaust is cited although such catalyst systems have not reached commercial application.     

Development of monolithic catalysts with low noble metal content for diesel vehicle emission control

The chemical composition of the catalyst containing Mn–Al–O and Pt has been developed on the basis of the synergetic effect of Pt and manganese oxides observed in the HC and CO oxidation reactions. This effect allows decreasing the Pt loading to 0.70 g/L in the catalytic systems of diesel engine exhaust gases and provides high activity in low temperature oxidation of light and heavy hydrocarbons, and high thermal stability. It has been found that the catalytic activity of Pt–Mn–Al monolithic catalysts in butane oxidation and DIESEL tests depends on the Pt precursor and Pt loading. At similar Pt loadings (1.06 g/L), the catalytic activity increases in the order H₂PtCl₆~H₂[Pt(OH)₆] < Pt(NO₂)₂(NH₃)_2. When one Pt precursor is used, the catalytic performance improves with Pt loading increase from 0 to 1.06 g/L, and being nearly constant at higher Pt loading (2.65 g/L).     

改性塑料在汽车行业中的发展状况

结合改性塑料的应用前景及汽车工业“以塑代钢”、“以轻代重”的发展趋势,综述了聚丙烯(PP)、尼龙(PA)、聚碳酸酯(PC)、聚苯醚(PPO)、聚甲醛(POM)五类材料改性的最新研究成果及其在汽车零部件上的最新应用情况,探讨了改性塑料行业的技术发展趋势和行业应用趋势.     

稀土钙钛矿型复合氧化物在汽车尾气净化中的应用

阐述了汽车尾气净化工艺中替代贵金属催化剂的必要性和可能性,评述了稀土钙钛矿复合氧化物在三效催化剂中的作用,指出这类贱金属催化剂是研制、开发三效汽车排气催化剂的重要方向。     

汽车催化剂技术发展及研究概况

采用催化剂技术是治理汽车排放污染的重要措施之一。汽车排气催化剂已经和正在被广泛应用。本文详细地评述了国内外近30年的汽车排气催化剂研究工作,包括相关法规标准、各种类型的催化剂、实验、理论研究及表征评价方法。     

Development of Monolithic Catalysts with Low Noble Metal Content for Diesel Vehicle Emission Control

Monolith washcoated catalysts with potential for diesel emission control have been developed. Two types of catalysts have been prepared for further study: (1) MnO _x supported on granulated -Al₂O₃, (2) MnO _x supported on cordierite monolith washcoated with -Al₂O₃. Both catalysts have been calcined at 500 and 900 °C and subsequently modified by doping with 0.1–1.0 wt% of Pt or Pd. The influence of the concentration of both manganese oxide (0–10 wt%) and noble metals Pt and Pd in the range 0–1.0 wt% on the catalytic activity in methane oxidation has been studied. Comparison of the catalytic activity of MnO _x /Al₂O₃ and MnO _x + Pt(Pd)/Al₂O₃ with that of a standard 1 wt%Pt/Al₂O₃ catalyst shows the existence of a synergetic effect. This effect is more pronounced for the samples calcined at 900 °C. The developed monolithic catalysts MnO _x + Pt(Pd)/Al₂O₃ demonstrate higher activity and thermal stability (up to 900 °C) compared to the commercial monolithic catalyst (TWC's).