Development in Process of Direct Decomposition of Nitrogen Monoxide over Copper Ion-exchanged Zeolite Catalysts

铜离子交换沸石催化剂直接分解一氧化氮工艺的研究进展

基本信息

批准号：
01850185
负责人：
IWAMOTO Masakazu
金额：
$ 4.22万
依托单位：
Hokkaido University (1990-1991)University of Miyazaki (1989)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01850185/
关键词：
Zeolite Copper Ion Exchange Nitrogen Monoxide Direct Decomposition

项目摘要

Direct decomposition and selective reduction of nitrogen monoxide over copper ion-exchanged zeolite catalysts are proposed as new methods for removal of NO. The copper ion-exchanged ZSM-5 zeolite (Cu-Z) was the most active catalyst for decomposition of NO. The activity of Cu-Z zeolites increased with increase in the exchange level. The zeolites with copper ion-exchange levels of 100% or more, which could be prepared by repeating ion exchange of the ZSM-5 zeolite using aqueous copper (II) acetate solution or addition of ammonia into the aqueous copper (II) nitrate solution, showed significantly high activity even in the presence of oxygen and at high GHSV region. It was clarified concerning Cu-Z, by using IR, ESR, phosphorescence, TPD, and CO adsorption measurements that (1) the Cu^<2+> ions exchanged into zeolite were reduced to Cu^+ and/or Cu^+-Cu^+ through evacuation at elevated temperature, (2) after exposure to oxygen at 773 K and subsequent evacuation, about 40% copper ions in zeo … More lite existed as Cu^+ ions, (3) the NO^- species formed by adsorption of NO on Cu^+ would be an intermediate in the NO decomposition, and (4) redox cycle of Cu^+<@2<@>D2 <@D1>@>D1Cu<@D12+@>D1 in the zeolite is probably a key step to achieve the decomposition reaction. Selective reduction of NO by hydrocarbon in the presence of oxygen was first found by the authors and Cu-Z was remarkably effective for NO removal at temperatures as low as 473-573 K. The activity for this selective reduction in NO+C<@D23@>D2H<@D26@>D2+O<@D22@>D2 system was not poisoned very much by addition of SO<@D22@>D2. The conversion into N<@D22@>D2 was changed to 85% (773 K) in the presence of SO<@D22@>D2, from 100% in the absence of SO<@D22@>D2, which is in contrast with the fact that the catalytic activity for direct decomposition of NO was completely lost on adding the same amount of SO<@D22@>D2. Furthermore, the reduction rate over Cu-Z at 525 K was higher than those over H-zeolite and alumina catalysts at 673 and 773 K, respectively, which have been reported to be active, after findings by the authors. Less

在铜离子交换的沸石催化剂上，一氧化氮的直接分解和选择性降低被认为是去除NO的新方法。铜离子交换的ZSM-5沸石（CU-Z）是分解NO的最活跃的催化剂。 Cu-Z沸石的活性随交换水平的增加而增加。具有100％或以上的铜离子交换水平的沸石，可以通过使用乙酸水溶液（II）醋酸溶液重复离子交换ZSM-5沸石来制备，或在氧气和高GHSV区域的存在下，氨（II）硝酸盐溶液中的氨（II）硝酸盐溶液也具有显着高度的高度。通过使用IR，ESR，磷光，TPD和CO增加了有关Cu-Z的澄清，该测量值（1）（1）Cu^<2+>离子变为Zeolite，将变成Zeolite变为Zeolite，将其降低至Cu^+和/或Cu^+和/或Cu^+ -Cu^+ -Cu^+通过在高度的温度下撤离，（2）在773 k exe exe exy中，并在773 k中进行了撤离，并将 zeo … More lite existed as Cu^+ ions, (3) the NO^- species formed by addorption of NO on Cu^+ would be an intermediate in the NO decomposition, and (4) redox cycle of Cu^+<@2<@>D2 <@D1>@>D1Cu<@D12+@>D1 in the zeolite is probably a key step to achieve the decomposition reaction. Selective reduction of NO by hydrocarbon in the presence of oxygen was first found by the authors and Cu-Z was remarkably effective for NO removal at temperatures as low as 473-573 K. The activity for this selective reduction in NO+C<@D23@>D2H<@D26@>D2+O<@D22@>D2 system was not poisoned very much by addition of SO<@D22@>D2.在SO <@d22@> d2存在下，转换为N <@D22@> D2的转换更改为85％（773 K），从SO <@d22@> d2的情况下，从100％开始，这与添加SO <@D2222222222222222222的直接分解相反。此外，在525 K处的Cu-Z的降低速率分别高于H-唑来醇和氧化铝催化剂的673和773 K的降低速率，据报道在作者发现后，这些速率分别是活性的。较少的