• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied Surface Science >Linear nanoscale clusters of CuO in Cu-ZSM-5 catalysts
【24h】

Linear nanoscale clusters of CuO in Cu-ZSM-5 catalysts

机译：Cu-ZSM-5催化剂中CuO的线性纳米级簇

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The electron states of copper have been studied by ESR and UV-Vis as a function of the method used for preparation of Cu-ZSM-5 (ion-exchange, wet impregnation, and deposition), synthesis conditions (pH of copper solution, copper precursor, temperature, etc.) and copper loading. For calcined Cu-ZSM-5 samples treated under vacuum at 400℃, axial ESR spectra of O~- ion radicals (g_⊥ = 2.05, g_‖ = 2.02), which are presumably assigned to linear -O~--Cu~+-O~- -Cu~+-O~- -chains in zeolite channels, are observed. The same samples treated under vacuum at 150-400℃, exhibit UV-Vis absorption bands at the unexpected region of 18,000-23,000 cm~(-1). They are assigned to the ligand-metal charge transfer bands in -O~(2-)-Cu~(2+)-O~(2-)-Cu~(2+)-O~(2-)-like chains in the zeolite channels. Along with these states, isolated octahedral Cu~(2+) ions with different extents of tetragonal distortion (absorption band (a.b.) 12,500-14,000 cm~(-1)) and clustered copper oxide species (charge transfer band (CTB) 27,000-32,000 cm~(-1)) are also observed.
机译：通过ESR和UV-Vis研究了铜的电子态，该方法与Cu-ZSM-5的制备方法（离子交换，湿法浸渍和沉积），合成条件（铜溶液的pH，铜前驱体，温度等）和铜负载。对于在400℃下真空处理的煅烧Cu-ZSM-5样品，O〜-离子自由基的轴向ESR光谱（g_⊥= 2.​​05，g_‖= 2.02）被推测为线性-O〜--Cu〜+在沸石通道中观察到-O --- Cu-+-O ---链。在150-400℃的真空下处理的相同样品在18,000-23,000 cm〜（-1）的意外区域显示UV-Vis吸收带。它们被分配给-O〜（2-）-Cu〜（2 +）-O〜（2-）-Cu〜（2 +）-O〜（2-）链中的配体金属电荷转移带在沸石通道中。与这些状态一起，分离出具有不同程度的四边形畸变（吸收带（ab）12,500-14,000 cm〜（-1））和簇状氧化铜物质（电荷转移带（CTB）27,000-）的八面体Cu〜（2+）离子还观察到32,000 cm〜（-1））。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号