共查询到19条相似文献,搜索用时 78 毫秒
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为满足国Ⅳ排放要求,必须尽可能提高催化剂的耐高温性能和降低起燃温度。各组分与去离子水混合,研磨10 h,90%的粒子直径在25 μm以下,然后分次涂敷到陶瓷蜂窝上,150 ℃干燥5 h,450 ℃焙烧活化1 h。得到贵金属含量为0.95 g·L-1、Pd与Rh质量比为7∶1,Pd内涂层和Rh外涂层的催化剂,该催化剂的起燃温度分别为:T50(CO)=192.0 ℃,T50(NOx)=201.9℃,T50(HC)=206.2 ℃,高温老化后的T50(CO)=228.1 ℃,T50(NOx)=235.1 ℃,T50(HC)=225.2 ℃。将该催化剂应用于夏利轿车上,常温冷启动,低温冷启动和耐久性均能达到国Ⅳ标准,可以实际装车使用。 相似文献
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分别将三种不同Rh涂层制备成双涂层整体式三效催化剂,对不同涂层材料分别迚行比表面积(BET)分析、H2-TPR测试分析并考察各三效催化剂对C3H8催化转化的影响。结果表明Rh涂层材料影响了整体式三效催化剂C3H8催化转化的抗高温老化性能、起燃温度、完全转化温度及空燃比窗口。 相似文献
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对UOP公司催化重整催化剂领域相关专利进行了检索,从专利申请趋势、技术区域分布、专利技术布局和在中国专利申请情况等方面对其专利技术进行分析。UOP公司在催化重整催化剂领域进行了大量的研究工作,自1943年开始在该领域申请专利,并不断加强其在世界主要国家的专利布局,在美国和中国等10 余个国家申请了相关专利,专利技术主要涉及含分子筛催化剂、含贵金属催化剂和分子筛催化剂等制备技术。UOP公司催化重整催化剂专利技术的研发主要集中在铂基多金属催化剂的优化、催化剂载体性能的进一步提高以及新助剂的研究,目前主要是通过对不同类型和含量的助金属进行研究,研发高活性、高产率、高选择性、低生焦、抗磨性能好的催化重整催化剂,其催化剂呈现系列化发展。 相似文献
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Baik Joon Hyun Kwon Hyuk Jae Kwon Yong Tak Nam In-Sik Oh Se H. 《Topics in Catalysis》2007,42(1-4):337-340
A Pd catalyst is particularly effective for the oxidation of CO and C3H6 at low temperatures, while the Pt/Rh/Ce catalyst is active for NO reduction. The TWC activity of both catalysts generally
decreased as the catalyst mileage increased. However, the NO reduction activity was less affected by catalyst aging compared
to the oxidation reactions. The selectivity of the catalysts in favor of the CO–O2 reaction (vs. C3H6–O2 reaction) in the O2 partitioning experiments became less pronounced as the catalyst aged. The NO partitioning experiments reveal the superior
capability of H2 in NO reduction to the other reductants (CO and C3H6) examined in the present study. The reactivities of NO with both H2 and CO were found to decrease upon catalyst aging, resulting in decreased overall NO removal activity. 相似文献
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Michael D. Turner Robert L. Laurence K.S. Yngvesson Wm. Curtis Conner 《Catalysis Letters》2001,71(3-4):133-138
Recent studies suggest that microwave energy can be employed in catalysis and that the results differ from conventional heating. The influence of microwave energy on automotive exhaust catalysis in the presence and absence of a catalyst poison (SO2) was studied. The conclusion is that microwave energy can induce carbon monoxide (CO) lightoff (the temperature where 50% of final conversion is achieved) more efficiently than conventional heating and can reverse the poisoning by SO2 for a commercial three-way catalyst. 相似文献
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Pd-only three-way catalysts prepared by the sol–gel method were investigated by the three-way catalytic performance test with a simulated exhaust gas in a continuous U-tube quartz reactor at a gas hourly space velocity of 72 000 h−1. The catalysts were characterized with XRD, XPS, BET surface area and pore volume. The activity and thermal stability of the Pd–Al2O3 catalyst prepared at pH 10 were superior to those at pH 4 during hydrolysis and condensation, which could be explained by the anchoring effect. Zr and V were found to be good promoters for the enhancement of the thermal stability and SO2 resistance, respectively. Optimally formulated catalyst, Pd(1)–V(2)–Zr(10)–Al2O3, was thermally stable up to 900oC and showed a much more improved low-temperature activity and excellent SO2 resistance. 相似文献