...
首页> 外文期刊>The journal of physical chemistry, C. Nanomaterials and interfaces >Formation, Characterization, and Reactivity of Adsorbed Oxygen on BaO/Pt(111)
【24h】

Formation, Characterization, and Reactivity of Adsorbed Oxygen on BaO/Pt(111)

机译:BaO / Pt吸附氧的形成,表征和反应性(111)

获取原文
获取原文并翻译 | 示例
           

摘要

The formation of adsorbed O (O_(ad)) species and their reactivities in CO oxidation on BaO/Pt(111) (at two BaO coverages) were studied with temperature programmed desorption (TPD), infrared reflection absorption (IRA), and X-ray photoelectron (XP) spectroscopies. In neither of these two systems was the Pt(111) surface completely covered with BaO. On the system with lower BaO coverage (~45% of the Pt(111) surface is covered by BaO), two different O_(ad) species form following the adsorption of O2 at 300 K: O adsorbed on the BaO-free Pt(111) sites (O_(Pt)) and at the Pt-BaO interface (O_(int)). On the system with higher BaO coverage (~60% of the Pt(111) surface is covered by BaO), two types of O_(int) are seen at the Pt-BaO interface. The desorption of O_(Pt) from the BaO-free portion of the Pt( 111) surface gives an O2 desorption peak with a maximum desorption rate at ~690 K. Migration of O_(int) to the Pt(111) sites and their recombinative desorption give two explosive desorption features at ~760 and ~790 K in the TPD spectrum. The reactivities of these O_(ad) species with CO to form CO2 follow their sequence of desorption; i.e., the Opt associated with the BaO-free Pt(111) surface, which desorbs at 690 K, reacts first with CO, followed by the O_(int) species at the Pt—BaO interface (first the one that desorbs at ~760 K and finally the one that is bound the most strongly to the interface, and desorbs at ~790 K).
机译:吸附的O的形成(O_(AD))的物种和它们在CO氧化上的BaO /铂(111)的反应性(在两个BaO的覆盖范围)的患者进行程序升温脱附(TPD),红外反射吸收(IRA),和X射线光电子(XP)光谱。在既没有这两个系统的完全覆盖的BaO在Pt(111)表面。上具有较低的BaO覆盖(〜铂(111)表面的45%是由BaO的覆盖)的系统中,两个不同的O_(广告)物种形式以下O2的在300K吸附:o吸附在保自由铂( 111)网站(O_(Pt)的),并在铂界面的BaO(O_(INT))。上具有较高的BaO覆盖系统(〜铂(111)表面的60%被覆盖的BaO),两种类型的O_(INT)的在所述的Pt-BaO的界面观察。 O_(Pt)的从Pt组成的保自由部分解吸(111)面得到具有在〜690的最大解吸速率的O 2脱附峰O_(int)以在Pt(111)位点和K.迁移其recombinative解吸得到两种炸药解吸设有在〜760,并在TPD谱〜790ķ。用CO这些O_(广告)物种形式的CO 2的反应性按照他们的解吸序列;即,与保游离的Pt(111)表面,其解吸在690ķ相关联的选项,发生反应先用CO,随后在铂的BaO接口O_(INT)物种(第一的一个,在〜760脱附K和最后一个绑定的最强烈的接口,在解吸〜790 K)。

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