激光拉曼光谱研究NiMoP浸渍液活性组分的结构Ⅱ.不同有机添加剂的影响

Study on the structure of active phase in
NiMoP impregnation solution using Laser Raman spectroscopy
Ⅱ. Effect of organic additives

  • 摘要: 采用激光拉曼光谱(LRS)技术对添加有乙二醇和柠檬酸的NiMoP浸渍液和用该浸渍液制备的NiMoP/Al2O3催化剂进行了表征,研究了乙二醇和柠檬酸含量对NiMoP浸渍液及浸渍过程中活性相组成、结构的影响。结果表明,乙二醇使NiMoP(0.063)浸渍液中Hx\PMo11O39\(7-x)- 或Hx\PMo9O31\(3-x)-及Hx\PMo12O40\(3-x)- 杂多阴离子结构转化成Hx\P2Mo5O23\(6-x)- 结构,而柠檬酸能保持NiMoP(0.063)浸渍液中Hx\P2Mo5O23\(6-x)-、Hx\PMo11O39\(7-x)- 或Hx\PMo9O31\(3-x)-及Hx\PMo12O40\(3-x)-杂多阴离子结构共存,但导致Hx\P2Mo5O23\(6-x)-含量降低,Hx\PMo12O40\(3-x)-含量升高。相对乙二醇而言,柠檬酸有机添加剂能够更有效地阻止浸渍过程中各杂多阴离子结构在载体氧化铝孔道中的分解。

     

    Abstract: Laser Raman spectroscopy (LRS) was used to characterize the NiMoP impregnant with different contents of glycol and citric acid as well as dried Al2O3 impregnated with this NiMoP impregnant. The effect of glycol and citric acid on the structure of active phases in NiMoP impregnant and during the impregnation process was investigated. The results indicated that with glycol as the additive in the NiMoP(0.063) impregnant, the active phases like Hx\PMo11O39\(7-x)- or Hx\PMo9O31\(3-x)- and Hx\PMo12O40\(3-x)- are converted to Hx\P2Mo5O23\(6-x)- . With citric acid as the additive, Hx\P2Mo5O23\(6-x)-, Hx\PMo11O39\(7-x)- or Hx\PMo9O31\(3-x)- and Hx\PMo12O40\(3-x)- are present together in the NiMoP(0.063) impregnant; however, citric acid leads a decrease of Hx\P2Mo5O23\(6-x)- content but an increase of Hx\PMo12O40\(3-x)-. Compared with glycol, during the impregnation of alumina with the NiMoP impregnant, citric acid is more effective in preventing the active phases from being decomposed in the cavities of alumina.

     

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