溶液pH值及钨前驱体影响含钨过氧物种结构的Raman光谱研究  

Raman Study of Transformation Behaviors of Tungsten-containing Peroxo Species Affected by Different Precursors and Solution Acidities

作　　者：林海强[1] 李华明[2] 于贤勇[1] 翟和生[1] 袁友珠[1] 万惠霖[1] 

机构地区：[1]厦门大学化学系固体表面物理化学国家重点实验室,厦门361005 [2]海南师范学院化学系,海口571158

出　　处：《化学学报》2004年第18期1780-1784,共5页Acta Chimica Sinica

基　　金：福建省自然科学基金 (No.E0 1 1 0 0 0 5)资助项目

摘　　要：识别水溶液体系中含过渡金属W ,Mo的过氧物种结构是探索烯烃、醇及醛等与双氧水催化选择氧化反应机理的关键所在 ,本研究借助高灵敏度的共焦显微Raman光谱表征手段 ,考察了Na2 WO4,(NH4) 10 [H2 W12 O42 ]和H3 PW12 O40 三种含钨前驱体在不同pH值条件下与过量双氧水作用产生的主要过氧物种的结构特征 ,推测在酸性较强 (pH <2 3 )的条件下三者产生的主要过氧物种结构相同 ,可能是单核式的 [WO2 (O2 ) 2 (H2 O) ] 2 -,而二聚态或多聚态的过氧物种几乎不存在于体系中 ;此外 ,还首次建立了通过Raman光谱来半定量测定双氧水浓度的分析方法 ,并尝试用于双氧水催化分解的动力学研究中 .Tungsten and molybdenum compounds act as efficient catalysts for oxidations of olefins, alcohols or aldehydes by hydrogen peroxide. The nature of the peroxo species formed in solutions with different precursors including Na2WO4, (NH4)(10)[H2W12O42] and H3PW12O40 in the presence of excess H2O2 has been studied by Raman spectroscopy. Regardless of tungsten-containing precursors, mononuclear species of [WO2(O-2)(2) (H2O)](2-) is likely principal peroxo species under the conditions with low pH (pH < 2.3) and excess H2O2, and other dimeric or polymeric species are almost absent. Moreover, novel method for determining H2O2 concentrations by Raman spectroscopic analysis was established and applied in kinetics study of H2O2 catalytic dismutation to H2O and O-2.

关 键 词：溶液PH值 钨前驱体 含钨过氧物种 结构 RAMAN光谱 双氧水 杂多酸 催化剂 

分 类 号：O657.3[理学—分析化学]