用于氢同位素交换分离的新型Pt/疏水陶瓷催化剂

Novel Hydrophobic Pt/Inorganic Catalyst Used in Hydrogen Isotope Exchange Reaction

  • 摘要: 为提升疏水催化剂性能并扩展其应用范围,以柱状(ø=5 mm)多孔陶瓷为载体,在载体表层构筑氧化铈(CeO2)微纳结构为载体提供疏水环境,采用浸渍还原法制备用于氢同位素交换分离的新型Pt/疏水陶瓷催化剂。为验证新型疏水催化剂实用性,以X射线衍射(XRD)、扫描电镜(SEM)、X光电子能谱(XPS)、一氧化碳(CO)脉冲吸附、能谱(EDX)对催化剂性能进行综合表征,并采用气汽并流方式测试催化剂催化活性。结果表明,新型陶瓷载体疏水性优良,疏水结构对载体孔结构性能影响较小;疏水层使浸渍液对载体浸润能力下降,铂粒子分散度及零价铂含量降低;浸润能力下降使前驱体多沉积在载体表层而较难渗入载体内部,表层铂粒子含量高,使反应物的反应通道较短,相同时间内有更多的铂粒子参与反应。制得催化剂催化活性可达同种形状有机载体类催化剂催化活性的80%,冲淋12周后,催化活性下降比率小于5%,新型疏水催化剂催化活性及耐冲淋稳定性均较好,实用性佳,具有良好的应用前景。

     

    Abstract: To improve the performance of hydrophobic catalyst and extend its using range, this research adopted the porous columnar inorganic carriers (ø=5 mm) to prepare the hydrophobic catalyst used in hydrogen isotopes exchange reaction, the hydrophilic carriers became hydrophobic with the nanostructured CeO2 coating and the catalyst were then fabricated by convenient impregnation method. The samples were characterized by XRD、SEM、EDX、XPS and CO adsorption. The catalytic activity were tested through catalytic exchange reaction between hydrogen and saturated water vapor to investigate the effect of micro structured CeO2 on the catalyst properties. It turned out that the nano-CeO2 coating could build favorable hydrophobic environment for the catalysts and had almost no influence on the pore structure properties of carriers. Although the hydrophobic coating would lead to the decrease of Pt particle dispersion and metallic Pt content, it could make the Pt particles mostly deposit on the surface layer of the catalysts, which would make more Pt particle participate in the reaction at the same time. The catalytic activity of the novel Pt/inorganic catalyst could reach to 80% of the mature Pt/organic catalyst. After being flushed by water for 12 weeks, the catalytic activity of Pt/inorganic catalyst decreased less than 5%. The novel hydrophobic catalyst with good activity and stability was practical and had great application prospects.

     

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