催化学报

催化学报 ›› 2007, Vol. 28 ›› Issue (2): 131-136.

• 研究论文 • 上一篇    下一篇

含硫液体烃燃料水蒸气重整制氢Ⅰ. Pt/Ce0.8Gd0.2O1.9催化剂的制备、表征和抗硫性能

陈金春,刘晔,路勇,薛青松,高立达,王亚,何鸣元   

  1. 华东师范大学化学系, 上海市绿色化学与化工过程绿色化重点实验室, 上海 200062
  • 收稿日期:2007-02-25 出版日期:2007-02-25 发布日期:2011-01-28

H2 Production from Steam Reforming of High Energy Density Motor Fuel with Sulfu Ⅰ. Preparation, Characterization, and Sulfur Tolerance of Pt/Ce0.8Gd0.2O1.9 Catalyst

CHEN Jinchun, LIU Ye, LU Yong*, XUE Qingsong, GAO Lida, WANG Ya, HE Mingyuan   

  1. Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai 200062, China
  • Received:2007-02-25 Online:2007-02-25 Published:2011-01-28

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摘要： 以柠檬酸溶胶-凝胶法合成的具有萤石结构的Ce0.8Gd0.2O1.9(CGO)复合氧化物为载体,用初湿浸润法制备了负载型Pt催化剂. 纯异辛烷的重整反应结果显示, 600和800 ℃焙烧的催化剂达到了热力学平衡转化, 1000 ℃焙烧会导致Pt的聚集和氧化物的严重烧结,因而催化剂活性较差. 抗硫测试表明, 800 ℃焙烧的催化剂抗硫性能最好,在300 μg/g硫存在下, 100 h内异辛烷均接近完全转化; 在500 μg/g硫存在下催化剂仍表现出良好抗硫性能. 程序升温还原和X射线分析结果显示, 800 ℃焙烧时Pt与CGO载体间的相互作用最强,同时催化剂具有良好的热稳定性,这是催化剂具有抗硫性能并且抗硫作用持久的根本原因. 反应条件下噻吩硫完全转化成H2S, 硫的转化可能是通过氧化-还原机理进行的.

关键词: 铂, 稀土氧化物, 水蒸气重整, 异辛烷, 氢气, 硫中毒

Abstract: A high sulfur tolerant Pt catalyst was prepared using a fluorite-type Ce0.8Gd0.2O1.9[KG10x](CGO) oxide as the support that was synthesized by the citric acid sol-gel method. Sulfur tolerance of the catalyst was tested for the steam reforming of isooctane at 750 ℃ and isooctane WHSV of 1.0 h-1 with a steam/carbon molar ratio of 3 using thiophene as the sulfur source. The catalyst calcined at 800 ℃ maintained its activity and selectivity in the entire 100 h test with 300 μg/g or more sulfur, whereas the catalyst calcined at 600 ℃ lost its activity slowly in this course because of both sulfur poisoning and its poor thermal stability. Temperature-programmed reduction and X-ray diffraction analyses, together with comparison of the activity of Pt/CGO with Ni/CGO and Pt/Al2O3, showed that the synergistic effect between CGO oxide and Pt at the interface existed while being enhanced and consolidated with the calcination treatment at 800 ℃, which made Pt immune to sulfur poison and active to convert thiophene sulfur into H2S. In addition, sulfur balance measurements together with diffuse reflectance infrared Fourier transform spectroscopy and microcoulomb titration for surface sulfur-containing species on the used catalyst suggested that thiophene sulfur was completely converted into H2S, probably complying with a redox mechanism.

Key words: platinum, rare earth oxide, steam reforming, isooctane, hydrogen, sulfur tolerance