激光拉曼光谱研究NiMoP浸渍液活性组分的结构
Ⅰ.磷含量的影响
Study on the structure of active phase in NiMoP impregnation solution using Laser Raman spectroscopy
Ⅰ.Effect of phosphorous content
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摘要: 采用激光拉曼光谱(LRS)分析技术对NiMoP浸渍液和浸渍于氧化铝载体后干燥样品进行了表征,研究了磷含量对NiMoP浸渍液中的活性相组成、结构以及浸渍过程中活性相结构变化的影响。结果表明,在磷酸含量较低的NiMoP浸渍液中活性组分主要有NixH6-2x\P2Mo5O23\、NixH7-2x\PMo11O39\ 或NixH3-2x\PMo9O31\及NixH3-2x\PMo12O40\杂多化合物结构,随着磷酸添加量的增加,后两种结构逐渐转化成第一种杂多化合物的结构;低磷含量浸渍液中的各种杂多化合物活性组分在浸渍过程中在氧化铝孔道中会发生分解,转变成七聚钼酸盐,提高浸渍液中的磷酸含量能够部分地阻止杂多化合物在载体氧化铝孔道中的分解。
Abstract: Laser Raman spectroscopy (LRS) was used to characterize the NiMoP impregnation solution and dried samples of NiMoP impregnated on γ-Al2O3. The effect of phosphorous content on the structure of the active phases in NiMoP impregnation solution and that during the impregnation process was studied. The LRS results indicate the active phases in NiMoP impregnation solution with lower phosphorous content are composed of several heteropoly compounds such as NixH6-2x\P2Mo5O23\, NixH7-2x\PMo11O39\ or NixH3-2x \PMo9O31\ and NixH3-2x\PMo12O40\. NixH6-2x\P2Mo5O23\ is dominant when phosphorous content increases. In addition, these active phases in NiMoP impregnation solution with lower phosphorous content are converted to seven poly-molybdate when the impregnation solution is impregnated into the cavities of γ-Al2O3, while higher phosphorous content hinders this conversion.