...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Catalysis science & technology >Gas-phase oxidation of ethanol over Au/TiO2 catalysts to probe metal-support interactions
【24h】

Gas-phase oxidation of ethanol over Au/TiO2 catalysts to probe metal-support interactions

机译：Au/TiO2催化剂上乙醇的气相氧化以探测金属支持的相互作用

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

Ethanol and oxygen were converted over titania and gold nanoparticles supported on titania to investigate the reactivity of the support, the influence of the metal, and the role of metal-support interactions. In addition to determining the degrees of conversion and the yields as a function of temperature, temperature-programmed desorption and diffuse reflectance infrared spectroscopy were performed in fixed-bed reactors under continuous flow conditions. Over pure TiO2 mainly selective oxidative dehydro-genation to acetaldehyde and water and, to a minor extent, total oxidation to CO2 and H2O were found to occur above 500 K. The presence of Au nanoparticles additionally induced the selective oxidation to acetaldehyde and H2O at temperatures below 400 K. Thus, the Au/TiO2 catalyst shows Afunctional properties in oxygen activation needed for the selective oxidation of ethanol. Ethoxy species were detected by IR spectroscopy, which are identified as intermediate species in ethanol conversion. In contrast, strongly bound acetates and acetic acid acted as catalyst poisons for the selective low-temperature oxidation route but not for the high-temperature route. Selective low-temperature oxidation is assumed to occur at the perimeter of the Au nanoparticles, which additionally enhance the high-temperature oxidation route on TiO2 pointing to a Mars-van Krevelen mechanism based on an enhanced reducibility of TiO2.
机译：将乙醇和氧气转化为二氧化钛和金纳米颗粒，这些二钛和金纳米颗粒研究了支持的反应性，金属的影响以及金属支持相互作用的作用。除了确定转化率和屈服程度与温度的函数之外，在连续流动条件下，在固定层反应器中进行了温度填充和弥漫性反射率红外光谱。在纯TiO2上，主要是选择性氧化脱氢脱氢脱氢对乙醛和水，并且在较小程度上，发现对CO2和H2O的总氧化发生在500 K以上。Au纳米颗粒的存在还诱导了选择性氧化的乙醛和H2O的选择性氧化。因此，Au/TiO2催化剂在400 K以下，显示了乙醇选择性氧化所需的氧气激活中的副本性能。通过红外光谱检测乙氧基化物质，在乙醇转化率中被鉴定为中间物种。 In contrast, strongly bound acetates and acetic acid acted as catalyst poisons for the selective low-temperature oxidation route but not for the high-temperature route.假定选择性低温氧化发生在Au纳米颗粒的周长上，该颗粒的周长还增强了基于TIO2的可降低性的TiO2上的高温氧化途径，该途径指向Mars-Van Krevelen机制。

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