催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (3): 275-280.

• 研究论文 • 上一篇    下一篇

Ce和Mg改性的γ-Al2O3负载Pt催化剂催化乙二醇水相重整制氢

白赢,卢春山,马磊,陈萍,郑遗凡,李小年   

  1. 浙江工业大学工业催化研究所,绿色化学合成技术国家重点实验室培育基地, 浙江杭州 310032
  • 收稿日期:2006-03-25 出版日期:2006-03-25 发布日期:1984-10-26

Hydrogen Production by Aqueous-Phase Reforming of Ethylene Glycol over Pt Catalysts Supported on γ-Al2O3 Modified with Ce and Mg

BAI Ying, LU Chunshan, MA Lei, CHEN Ping, ZHENG Yifan, LI Xiaonian*   

  1. State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Institute of Industrial Catalysis, Zhejiang University of Technology, Hangzhou 310032, Zhejiang, China
  • Received:2006-03-25 Online:2006-03-25 Published:1984-10-26

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摘要： 采用浸渍法制备了Ce和Mg改性的 γ-Al2O3 负载Pt乙二醇水相重整制氢催化剂. 采用催化活性评价、N2物理吸附、CO化学吸附、X射线衍射(XRD)和程序升温还原(TPR)等手段系统研究了催化剂的活性、选择性及物化性质. 实验结果表明, Ce和Mg改性的 γ-Al2O3 负载Pt催化剂的活性明显高于Pt/γ-Al2O3 催化剂. 在498 K和2.58 MPa条件下,乙二醇的转化率由72.3%提高到100%, 氢的选择性接近100%. 在Pt/(Ce)γ-Al2O3 和Pt/(Mg)γ-Al2O3 催化剂的XRD谱中,除了 γ-Al2O3 特征峰外,还分别出现了CeO2和Mg-Al层状化合物及微弱的Mg-Al尖晶石结构化合物的特征峰. Ce的存在促进了Pt对乙二醇的吸附-裂解作用和CO水煤气变换反应; Mg的存在中和了 γ-Al2O3 表面的酸性,增加了载体的碱性中心,影响了PtCl2-6的分散,抑制了乙二醇的脱水反应.

关键词: 铂, 铈, 镁, 氧化铝, 负载型催化剂, 改性, 乙二醇, 水相重整, 制氢

Abstract: Pt catalysts supported on γ-Al2O3 modified with Ce or Mg were prepared by impregnation with a H2PtCl6 aqueous solution and used in the hydrogen production by aqueous-phase reforming of ethylene glycol. Catalytic activity testing, N2 physical adsorption, CO chemical adsorption, X-ray diffraction (XRD), and temperature-programmed reduction (TPR) were employed to evaluate the activity, hydrogen selectivity, and physicochemical properties of the catalysts. The results indicate that Pt catalysts supported on γ-Al2O3 modified with Ce or Mg show higher activity than the Pt/γ-Al2O3 catalyst. At the temperature of 498 K and pressure of 2.58 MPa, the conversion of ethylene glycol is increased from 72.3% over Pt/γ-Al2O3 to 100% over Pt/(Ce)γ-Al2O3 or Pt/(Mg)γ-Al2O3, and the selectivity for hydrogen almost reaches 100%. The characteristic peaks attributed to CeO2, Mg-Al layer chemical component, and Mg-Al spinel have been observed besides the γ-Al2O3 peak in the XRD patterns of Pt/(Ce)γ-Al2O3 and Pt/(Mg)γ-Al2O3. The presence of Ce not only increases the dispersion of Pt on the surface of γ-Al2O3, but also improves the adsorption-cracking of ethylene glycol on Pt and water-gas shift reaction; while the presence of Mg neutralizes the acidity of γ-Al2O3, influences the dispersion of PtCl2-6, and inhibits the dehydration of ethylene glycol.

Key words: platinum, cerium, magnesium, alumina, supported catalyst, modification, ethylene glycol, aqueous-phase reforming, hydrogen production