【摘要】 采用室温沉淀法制备了一系列铯取代磷钨杂多酸盐(CsxH3-xPW12O40,x=0.5,1.0,1.5,2.0,2.5,3.0),考察了不同铯取代度对所制杂多酸盐结构及其催化苯甲醛氧化制苯甲酸反应性能的影响.利用液氮吸附-脱附(N2adsorption-desorption)、扫描电镜(SEM)、X-射线衍射(XRD)、傅里叶红外光谱(FT-IR)、固体紫外可见漫反射光谱(DR UV-vis)等手段进行了表征.结果表明:CsxH3-xPW12O40完好地保持了H3PW12O40的Keggin晶相;随着铯取代度x的增大,CsxH3-xPW12O40的颗粒逐渐均匀,同时晶胞参数逐渐减小,表面积和孔容则随之增大.在相同的实验条件下,所制CsxH3-xPW12O40均呈现出较高的催化活性:在Cs3PW12O40催化作用下,苯甲酸的收率达到72%,而其他催化剂作用下达到76%,均优于H3PW12O40的催化活性(71%).更多还原

【Abstract】 A series of cesiumsalts of 12-tungstophosphoric acid( CsxH3-xPW12O40) were synthesized by the precipitation method and analyzed by N2adsorption-desorption,SEM,XRD,FT-R,and DR UV-vis. The effect of different cesium ion exchange on structure and catalytic behavior of 12-tungstophosphoric acid for the oxidation of benzaldehyde with 30% H2O2was investigated. The results showed that all the sample sremained the primary Keggin structure of H3PW12O40. Moreover,the particles became more uniformity and the textural parameters increased with the increase of x in CsxH3-xPW12O40. Cs3PW12O40reached the largest surface area( 109. 1 m2/ g) and pore volume( 0. 121 9 cm3/ g). On the other hand,CsxH3-xPW12O40exhibited better catalytic activities than H3PW12O40( 71%). The yield of benzoic acid was about 72% and 76% over Cs3PW12O40and theothers.更多还原