Design and Development of Unique Photocatalytic Systems for the Decomposition of NOx

设计和开发用于分解氮氧化物的独特光催化系统

基本信息

批准号：
10044170
负责人：
ANPO Masakazu
金额：
$ 2.05万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10044170/
关键词：
Metal ion-implantation method TiOィイD22ィエD2 photocatalyst NOx decomposition Utilization of solar beam Cr ion-implanted TiOィイD22ィエD2 Utilization of visible light Ag ZSM-5 酸化チタン太陽光イオン注入法 NO光触媒分解反応ゼオライト ESR

项目摘要

Until now, photocatalytic reactions involving TiO2 photocatalysts for the decomposition of NOx were known to proceed only under UV light irradiation. In this research project, by the application of advanced metal ion-implantation with various transition metal ions such as V and Cr, it was found that novel TiO2 photocatalysts which absorb and operate efficiently under visible light irradiation for the decomposition of NOx could be developed. In-situ ESR and XAFS investigations revealed that the implanted V ions which exist as VィイD14+ィエD1 at the lattice position in place of TiィイD14+ィエD1 ion play a significant role in the shift in the absorption bands of TiO2 toward visible light regions. On the other hand, highly dispersed TiO2 catalysts anchored within the pore structure of the Y-zeolite by an ion-exchange method (Ti-Y zeolite) exhibited higher photocatalytic activity as compared to powdered TiO2. V or Cr ion-implantation on the Ti-Y zeolite also leads to a shift in the absorption band of the catalyst toward visible light regions and it was found that these V or Cr ion-implanted Ti-Y zeolites successfully decompose NOx under irradiation with visible light longer than 450nm, while maintaining just as a high photocatalytic activity as observed before applying ion-implantation. Furthermore, in-situ ESR and FT-IR investigations *lucidated the electron transfer from the photo-excited active site of the photocatalyst into the p anti-bonding molecular orbital of NO which led to a weakening of the N-O bond and initiated the decomposition of the NO molecule. It can be said that the present research has opened the way to many innovative possibilities, significantly to address urgent environmental problem and also as an important breakthrough in the utilization of solar energy.

迄今为止，已知涉及 TiO2 光催化剂分解 NOx 的光催化反应只能在紫外光照射下进行。在该研究项目中，通过应用先进的金属离子注入各种过渡金属离子（例如 V 和 Cr），实现了光催化反应。发现可以开发在可见光照射下有效吸收和分解 NOx 的新型 TiO2 光催化剂。原位 ESR 和 XAFS 研究表明。表明在晶格位置以 ViD14+D1 形式存在的 V 离子代替 TiD14+D1 离子在 TiO2 吸收带向可见光区域的移动中发挥了重要作用。通过离子交换法（Ti-Y沸石）在Y沸石的孔结构中表现出比Y沸石更高的光催化活性Ti-Y沸石上的V或Cr离子注入也导致催化剂的吸收带向可见光区域移动，并且发现这些V或Cr离子注入的Ti-Y沸石成功地分解了NOx。在超过 450nm 的可见光照射下，同时保持与应用离子注入之前观察到的高光催化活性此外，原位 ESR 和FT-IR 研究*阐明了电子从光催化剂的光激发活性位点转移到 NO 的 p 反键分子轨道，导致 N-O 键减弱并引发 NO 分子的分解。目前的研究为许多创新可能性开辟了道路，对解决紧迫的环境问题具有重要意义，也是太阳能利用的重要突破。