催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (1): 93-99.DOI: 10.3724/SP.J.1088.2011.00643

• 研究论文 • 上一篇    下一篇

焙烧气氛对 Ru/Al2O3 催化剂上甲烷部分氧化制合成气反应性能的影响

郑好转 1, 王梅柳 1, 华卫琦 2, 翁维正 1, 伊晓东 1, 黄传敬 1, 万惠霖 1   

  1. 1厦门大学固体表面物理化学国家重点实验室, 醇醚酯化工清洁生产国家工程实验室, 化学化工学院化学系, 福建厦门 361005; 2烟台万华聚氨酯股份有限公司, 山东烟台 264002
  • 收稿日期:2010-06-25 修回日期:2010-09-02 出版日期:2011-01-13 发布日期:2014-05-22

Effect of Calcination Atmospheres on the Performance of Ru/Al2O3 Catalyst for Partial Oxidation of Methane to Syngas

ZHENG Haozhuan1, WANG Meiliu1, HUA Weiqi2, WENG Weizheng1,*, YI Xiaodong1, HUANG Chuanjing1, WAN Huilin1,*   

  1. 1State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China; 2Yantai Wanhua Polyurethanes Co., Ltd., Yantai 264002, Shandong, China
  • Received:2010-06-25 Revised:2010-09-02 Online:2011-01-13 Published:2014-05-22

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摘要： 采用气相色谱、质谱和原位时间分辨红外光谱等技术对空气和 Ar 气氛中焙烧的 Ru/Al2O3 催化剂样品上甲烷部分氧化 (POM) 制合成气反应进行了跟踪, 并采用化学吸附、X 射线衍射、拉曼光谱和 H2-程序升温还原等技术对催化剂进行了表征. 结果表明, 在 Ru/Al2O3-Air 上 POM 反应出现振荡现象, 而在 Ru/Al2O3-Ar 上则可较平稳地进行. 经 600 oC 还原后, Ru/Al2O3-Air 上 Ru 的分散度仅为 1%, 而 Ru/Al2O3-Ar 上接近 9%. 这是导致两种样品上 POM 反应性能差异的主要因素. 新鲜催化剂上存在两类 Ru 物种, 分别是与载体相互作用较弱、较易还原的 RuO2 物种以及与载体相互作用较强、较难还原的 Ru-O-Al 物种. 前者在 POM 反应过程中被还原为金属 Ru0, 后者则可随温度的升降发生周期性的还原和氧化, 进而改变催化剂对 CH4 燃烧、重整或部分氧化等反应的相对活性, 导致 Ru/Al2O3-Air 上 POM 反应尾气中各组分的浓度随时间而发生振荡.

关键词: 钌, 氧化铝, 焙烧气氛, 甲烷, 部分氧化, 合成气, 振荡

Abstract: The catalytic performance for partial oxidation of methane (POM) to syngas over the Ru/Al2O3 catalyst calcined in air (Ru/Al2O3-Air) and Ar (Ru/Al2O3-Ar) was studied. Steady-state reactivity was observed on the Ru/Al2O3-Ar sample, whereas oscillations in CH4, CO, H2, CO2, and H2O were observed on the Ru/Al2O3-Air sample. Comparative studies using CO and O2 chemisorption, X-ray diffraction, Raman, and temperature-programmed reduction (TPR) techniques were carried out in order to elucidate the property-structure relationship of the samples. The Ru dispersion on Ru/Al2O3-Air was only 1%, whereas that on Ru/Al2O3-Ar was about 9%. The significant difference in the Ru dispersion on the two samples is the major factor affecting the POM reaction. Two types of Ru species, RuO2 species weakly interacting with Al2O3 and the Ru-O-Al species strongly interacting with the support, were identified by H2-TPR experiments on the fresh catalyst. The former species could be easily reduced by H2 (below 200 °C), while the latter can only be reduced by H2 at above 700 °C. During the POM reaction at above 600 °C, the RuO2 species were in the metal state, whereas the Ru-O-Al species could undergo cyclic redox transformation. Such transformation is responsible for the oscillation on Ru/Al2O3-Air sample.

Key words: ruthenium, alumina, calcination atmosphere, methane, partial oxidation, syngas, oscillation