权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Activation of Adsorbed Molecules in Zeolite by Means of Low-temperature Plasma and Photoexcitation

低温等离子体和光激发活化沸石中的吸附分子

基本信息

批准号：
15550120
负责人：
NAGAO Mahiko
金额：
$ 2.37万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15550120/
关键词：
copper ion-exchanged zeolite silver ion-exchanged zeolite dinitrogen adsorption nitrogen oxides plasma treatment photoexcitation infrared spectroscopy methane oxidation 酸化窒素吸着 XAFS測定

项目摘要

Zeolite that is a mixed oxide of silica and alumina has an ability of ion-exchange as well as a porosity, and hence, its internal space can be expected to use as a reaction field. Recently, we have reported that the copper ion-exchanged zeolite (ZSM-5 type) interacts strongly with nitrogen molecules even at room temperature, where the monovalent copper ion species (Cu^+) act as adsorption sites. In the present study, we intended to synthesize nitrogen compounds in the zeolite by means of plasma or photoexcitation and to elucidate the state of sites that reacted with nitrogen molecules as well as the reactivity of nitrogen compound formed. We also tried to prepare new catalysts by making use of the internal space of zeilite as a reaction field.Some results obtained are as follows. The copper ion-exchanged zeolites (CuZSM-5) prepared have different ability to adsorb nitrogen molecules, depending on the kind of counter ions involved in the exchanging solution ; the sample prepared by using a solution involving carboxylato (-COO^-) was found to be excellent in adsorption property. It was evident that the nitrogen molecules can be activated by plasma excitation to be adsorbed strongly on the zeolite surface (these species are removed by only treating at 573 K in vacuo). Furthermore, silver ion-exchanged zeolite (AgZSM-5) was also prepared, and by photoexciting it with ultraviolet rays, silver clusters consisting of about ten atoms were formed in the zeolite. It became cleat that the coexistence of such silver clusters and silver ions was necessary and sufficient condition for catalytic reaction (partial oxidation of methane).Two papers including these results have already been published in the scientific journals, and two more papers are submitted to the journals.

沸石是二氧化硅和氧化铝的混合氧化物，具有离子交换能力和多孔性，因此，其内部空间可以用作反应场。最近，我们报道了铜离子交换沸石（ZSM-5型）即使在室温下也与氮分子发生强烈的相互作用，其中单价铜离子（Cu^+）作为吸附位点。在本研究中，我们打算在沸石中通过等离子体或光激发合成氮化合物，并阐明与氮分子反应的位点状态以及所形成的氮化合物的反应活性。我们还尝试利用沸石内部空间作为反应场制备新的催化剂。得到的一些结果如下。制备的铜离子交换沸石（CuZSM-5）吸附氮分子的能力取决于交换溶液中涉及的反离子种类；用含有羧酸（- coo ^-）的溶液制备的样品具有优异的吸附性能。很明显，氮分子可以被等离子体激发激活，并在沸石表面强烈吸附（这些物质仅在真空中处理573 K即可去除）。此外，还制备了银离子交换沸石（AgZSM-5），通过紫外线光激发，在沸石中形成了约10个原子组成的银团簇。由此可见，银簇和银离子的共存是甲烷部分氧化催化反应的充分必要条件。包括这些结果在内的两篇论文已经在科学期刊上发表，另外两篇论文正在提交给这些期刊。