负载Ni催化剂用于乙二醇蒸汽重整制氢催化性能研究

Hydrogen production from steam reforming of ethylene glycol over supported nickel catalysts

  • 摘要: 采用等体积浸渍法和共沉淀法制备了Ni催化剂,在固定床反应器上考察了Ni负载量、焙烧温度、反应温度等因素对乙二醇低温重整制氢反应活性和选择性的影响。应用X射线衍射、氮物理吸附、H2程序升温还原等技术对负载型Ni催化剂进行了表征。结果表明,共沉淀法制备的Ni/CeO2催化剂具有较小的NiO颗粒与CeO2载体颗粒粒径,催化活性较高。添加少量氧化钴到Ni/CeO2催化剂中可使H2收率达72.6%,EG转化率达93.1%。在CeO2中添加Al2O3能提高负载Ni催化剂的活性,乙二醇转化率达94.0%,H2收率达67.0%;但添加SiO2则使其活性明显变差。

     

    Abstract: A series of nickel catalysts were prepared by the impregnation and co-precipitation methods and characterized by X-ray diffraction, nitrogen physisorption, and H2 temperature-programmed reduction. The effects of nickel loading, calcination temperature, reaction temperature, support modification and cobalt oxide addition on the catalytic activity and selectivity to H2 in the steam reforming of ethylene glycol were investigated. The results indicate that the nickel catalyst prepared by co-precipitation has smaller particle size and relatively higher activity in comparison with the catalyst prepared by impregnation. Adding a small amount of cobalt oxide to the Ni/CeO2 catalysts can enhance the catalytic activity; over the Ni-Co bimetallic catalyst, the yield of hydrogen reaches 72.6%. Modifying CeO2 with Al2O3, TiO2 and ZrO2 also has a certain influence on the catalytic activity and the Ni/CeO2-Al2O3 catalyst exhibits the highest activity, with an ethylene glycol conversion of 94% to gaseous products and a hydrogen yield of 67.0%. However, Ni/CeO2-SiO2 shows a very low activity in spite of its large surface area and pore volume.

     

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