化学学报 ›› 2005, Vol. 63 ›› Issue (6): 473-478. 上一篇    下一篇

研究论文

载体模板效应对氧化钯的热化学行为及其甲烷燃烧稳定性的影响

胡昱翔,蔡钒,方荣谦,李长有,杨乐夫*   

  1. (厦门大学化学系 物理化学研究所 固体表面物理化学国家重点实验室 厦门 361005)
  • 收稿日期:2004-05-12 修回日期:2004-11-28 出版日期:2005-03-28 发布日期:2010-12-10
  • 通讯作者: 杨乐夫

Methane Combustion over PdO Crystallite Manipulated by Support Template

HU Yu-Xiang, CAI Fan, FANG Rong-Qian, LI Chang-You, YANG Le-Fu*   

  1. (State Key Laboratory for Physical Chemistry of Solid Surface, Institute of Physical Chemistry, Chemistry Department, Xiamen University, Xiamen 361005)
  • Received:2004-05-12 Revised:2004-11-28 Online:2005-03-28 Published:2010-12-10
  • Contact: YANG Le-Fu

通过对PdO活性组分在单斜与四方型氧化锆载体上的热化学性质和催化活性进行比较性的研究显示, 单斜型ZrO2的表面原子能够满足与PdO的结构适应性匹配条件, 它可以通过界面原子的取向附生作用对表面PdO物种聚集形态进行调控, 从而促进PdO组分在单位载体表面上的分散. 此外, 升降温循环过程的DTG分析还表明, 单斜载体模板在反复的氧化还原循环中逐渐将结晶型PdO加工成取向附生型PdO, 不断改善PdO物种的氧迁移性质, 促进了热还原钯物种在高温区的氧化再生. 这两种载体效应有效地抑制了甲烷燃烧反应在高温区的活性振荡, 增加了燃烧的稳定性与催化剂的反应耐受性. 四方ZrO2晶相在载体内的掺杂将导致上述的载体效应受到明显抑制.

关键词: 催化燃烧, 钯催化剂, 取向附生, 热分析

A comparative investigation on the thermochemical and catalytic properties of palladium oxide crystallite supported on monoclinic or tetragonal-doped zirconia, demonstrated that by sharing the interfacial atoms with monoclinic zirconia, PdO crystallite aggregates at the aid of this epitaxy on the support template to acquire better dispersion. Moreover, tracking the heating-cooling cycles in air atmosphere, DTG analysis illustrated that the crystallized PdO gradually transforms into the epitaxial PdO species on the monoclinic zirconia and the improved mobility of oxygen in lattices promotes the oxidative regeneration of PdO at high temperature thereby. Combining the above two superiorities on aggregation forms of PdO, the template of monoclinic zirconia inhibits the high temperature deactivation of catalysts for methane combustion, meanwhile, increases the stability of combustion reaction and the sustainability of catalysts. However, the doping of tetragonal zirconia into monoclinic support muffles those advantages prominently.

Key words: catalytic combustion, palladium catalyst, epitaxy, thermal analysis