trz-Cl-Cu-PMo_(12)的合成、表征及催化氧化碘离子性能

Synthesis,Characterization and Catalytic Oxidation Iodine Ion Performance of trz-Cl-Cu-PMo_(12)

以H_(3)PMo_(12)O_(40)为前驱体,采用水热法使1,2,4-三氮唑-3-甲酸进行原位脱羧后,合成了1,2,4-三氮唑修饰的Keggin型多金属氧酸盐基金属-有机框架化合物(trz-Cl-Cu-PMo_(12)),并通过X射线单晶衍射、红外光谱(IR)、热重分析(TG)、X射线衍射(XRD)、扫描电子显微镜(SEM)及元素分析等手段对其进行了表征.X射线单晶衍射及元素分析表明,该晶体化合物的结构式为[Cu_(6)Cl_(0.5)(C_(2)H_(2)N_(3))_(4)][PMo_(12)O_(40)][Cu_(6)Cl_(0.5)(C_(2)H_(2)N_(3))_(4)],且由1个经典的Keggin型[PMo_(12)O_(40)]^(3−)和2个[Cu_(6)Cl_(0.5)(C_(2)H_(2)N_(3))_(4)]^(1.5+)以近似中心对称的方式构成,各组分之间通过超分子作用形成一维(1D)~三维(3D)结构.催化性能研究结果表明,该非均相催化剂在催化过氧化氢氧化碘离子为碘单质的反应中,经4 min 35 s到达终点时,反应速率高达1.42×10^(−5)mol·L^(−1)·s^(−1),碘单质生成速率提高了约551倍.催化剂重复使用8次,转化率仍然高达99.6%,表现出优异的催化活性,且具有良好的可重复性.

Using H_(3)PMo_(12)O_(40)as precursor,1,2,4-triazole-modified Keggin-type polyoxometalate-based metalorganic framework compound trz-Cl-Cu-PMo_(12)was synthesized by in situ decarboxylation of 1,2,4-triazole-3-carbo⁃xylic acid by hydrothermal method.It was characterized by X-ray single crystal diffraction,IR,TG,XRD,SEM,elemental analysis,etc.X-ray single crystal diffraction and elemental analysis showed that the structural formula of the crystalline compound is[Cu_(6)Cl0.(5 C_(2)H_(2)N_(3))_(4)][PMo_(12)O_(40)][Cu_(6)Cl_(0.5)C_(2)H_(2)N_(3))_(4)],and consists of one classic Keggin type[PMo_(12)O_(40)]^(3−),two[Cu_(6)Cl_(0.5)(C_(2)H_(2)N_(3))_(4)]^(1.5+)by approximately center symmetry,and one-dimen⁃sional(1D)to three-dimensional(3D)structures are formed between components through supramolecular interactions.Catalytic studies show that the heterogeneous catalyst is in catalytic oxidation of hydrogen peroxide with iodide ion as iodine ele⁃ment,the reaction rate reaches the end point after 4 min 35 s,the reaction rate is as high as 1.42×10^(−5)mol·L^(−1)·s^(−1),and the generation rate of iodine element is increased by about 551 times.The catalyst is reused 8 times,and the con⁃version rate is still as high as 99.6%,showing excellent catalytic activity and good repeatability.