物理化学学报 >> 1992, Vol. 8 >> Issue (04): 452-458.doi: 10.3866/PKU.WHXB19920406

研究论文 上一篇    下一篇

CeO2及Pt/CeO2催化剂上H2、O2的作用特性

陈燕馨; 李灿; 李文钊; 陈怡萱   

  1. 中国科学院大连化学物理研究所,大连 116023
  • 收稿日期:1991-02-11 修回日期:1991-08-10 发布日期:1992-08-15
  • 通讯作者: 陈燕馨

The Characteristic Behavior of H2 and O2 Over CeO2 and Pt/CeO2 Catalysts

Chen Yan-Xin; Li Can; Li Wen-Zhao; Chen Yi-Xuan   

  1. Dalian Institute of Chemical Physics, Academia Sinica, Dalian 116023
  • Received:1991-02-11 Revised:1991-08-10 Published:1992-08-15
  • Contact: Chen Yan-Xin

摘要: 采用TPD、TPR、FT-IR和TPEC等方法研究了CeO_2及Pt/CeO_2上H_2、O_2作用特性。结果表明, Pt促进CeO_2还原, 并形成高活动性氢物种。Pt的存在使吸H_2和放氢温度下阵达300 ℃。部分还原的CeO_2常温下吸附氧形成分子离子氧物种(O_2~-, O_2~(2-)), Pt的存在改变氧化铈催化剂在常温下氧吸附物种的形态, 以解离态存在。氧化铈上吸附的氧物种在升温时可部分脱附, 高于170 ℃时则转化为晶格氧。

关键词: 催化剂, 氧化, CeO2, Pt

Abstract: The characteristic behavior of H_2 and O_2 over CeO_2 and Pt/CeO_2 was studied by means of TPR, TPD, FT-IR and TPEC. The reduction of CeO_2 by H_2 is greatly promoted by supported Pt and highly labile adsorbed species is resulted. The temperatures of sorption and liberation of H_2 on Pt/CeO_2 are lowered by as much as 300 ℃ than on CeO_2. The oxygen adsorbed on partially reduced CeO_2 exists as dioxygen species(O_2~-,O_2~(2-)) at room temperature. On Pt/CeO_2 the oxygen species is altered and the dissociated species is formed even at ambient condition. The adsorbed oxygen on cerium oxide catalysts desorbs partly while the temperature is elevated and the retained oxygen is transformed into lattice oxygen ion above 170 ℃.

Key words: Catalyst, Oxidation, CeO2, Pt