催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (9): 1496-1501.DOI: 10.3724/SP.J.1088.2011.10506

• 研究论文 • 上一篇    下一篇

介孔 Al2O3 负载 PdO 催化甲烷燃烧反应性能

王月娟, 郭美娜, 鲁继青, 罗孟飞*   

  1. 浙江师范大学物理化学研究所, 先进催化材料省部共建教育部重点实验室, 浙江金华 321004
  • 收稿日期:2011-05-06 修回日期:2011-06-07 出版日期:2011-09-09 发布日期:2015-01-24

Mesoporous Alumina Supported PdO Catalysts for Catalytic Combustion of Methane

WANG Yuejuan, GUO Meina, LU Jiqing, LUO Mengfei*   

  1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China
  • Received:2011-05-06 Revised:2011-06-07 Online:2011-09-09 Published:2015-01-24

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摘要： 采用浸渍法制备了介孔 Al2O3 (M-Al2O3) 负载 PdO 催化剂, 考察了其催化 CH4 燃烧反应性能. 结果表明, 以 M-Al2O3 为载体的 PdO 催化剂活性比普通 Al2O3 载体高得多, 这很可能与 M-Al2O3 的孔道结构对 PdO 物种的限域作用有关. 随着 PdO/M-Al2O3 催化剂焙烧温度的升高, 甲烷催化燃烧活性先增加后降低, 其中 700 oC 焙烧的催化剂活性最高, 400 oC 反应时 CH4 转化率为 91%. 此时 Pd 物种主要以 PdO 颗粒形式高度分散在载体的介孔孔道内, 而高温焙烧时, Pd 物种主要以 Pd 和 PdO 的混合晶相存在. 尽管 900 oC 焙烧制得的催化剂上 CH4 的转化率降低, 但 TOF 值最大, 这可能与该催化剂中同时存在金属 Pd 和 PdO 有关.

关键词: 介孔氧化铝, 钯, 甲烷, 催化燃烧, 活性位

Abstract: Pd catalysts supported on mesoporous alumina (M-Al2O3) were prepared by an impregnation method and tested for CH4 catalytic combustion. PdO/M-Al2O3 was more active than the PdO catalyst supported on conventional Al2O3 because of a higher dispersion of PdO species induced by the mesoporous structure of M-Al2O3. Moreover, with increasing calcination temperature, the conversion of CH4 over PdO/M-Al2O3 catalysts first increased and then decreased. The best catalytic performance was obtained on the PdO/M-Al2O3 catalyst calcined at 700 oC, with a CH4 conversion of 91% at 400 oC. Pd species were mainly in mesoporous channels of the support in the form of highly dispersed PdO particles. When calcined at higher temperature, Pd species were in forms of crystalline Pd and PdO. A decline of reactivity and a higher turnover frequency were obtained on the PdO/M-Al2O3 catalyst calcined at 900 oC, which might be due to the co-existence of metallic Pd and PdO in the catalyst.

Key words: mesoporous alumina, palladium, methane, catalytic combustion, active site