The characteristics of CoMoP impregnation solution, dried and calcined samples of CoMoP impregnated with γ-Al2O3 were investigated by Raman spectroscopy. Effects of phosphorous content on the structures of the active phases in CoMoP impregnation solution during the impregnation process were studied. The results indicate that the active phases in CoMoP impregnation solution with lower phosphorous content are composed of several heteropoly compounds, such as CoxH6-2x[P2Mo5O23 ] , CoxH7-2x[PMo11 O39 ] or CoxH3-2x[ PMo9O31] and CoxH3-2x [ PMo12 O40]. CoxH6-2x [ P2Mo5O23 ] is dominant in CoMoP impregnation solution when phosphorous content increases. When the impregnation solution is impregnated into the cavities of γ-Al2O3, higher phosphorous content prevents CoxH6-2x [ P2Mo5O23 ] from converting to seven poly-molybdate. The presence of tetrahedral and octahedral Mo species is attributed to the interaction between Mo and P in the active phases.%采用激光拉曼光谱技术(LRS)对CoMoP浸渍液以及浸渍后的样品进行表征,研究了磷含量对CoMoP浸渍液中活性相前躯体结构的影响以及在浸渍后处理过程中对活性相结构的影响.实验结果表明,当CoMoP浸渍液中磷含量较低时,活性组分主要以CoxH6-2x[P2Mo5O23]、CoxH7-2x[PMo11O39]或CoxH3-2x[PMo9O31]以及CoxH3-2x[PMo12O40]结构存在,随着磷添加量的增加,后3种结构转化成CoxH6-2x[P2Mo5O23].提高磷含量有利于抑制活性组分在氧化铝表面分解成七聚钼酸盐.活性组分在载体吸附和催化剂焙烧过程中,在Mo和P之间存在相互作用,[P2Mo5O23]6-结构在焙烧过程中会发生解离.干燥样品经过高温焙烧后,催化剂中出现四面体配位和八面体配位的钼物种.
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