Zn取代的磷钨酸季铵盐无溶剂氧化苯甲醇合成苯甲醛

合成了一系列过渡金属Zn取代的Keggin型磷钨杂多酸的季铵盐,采用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)等方法表征了杂多化合物的结构.并将其用于苯甲醇无溶剂氧化合成苯甲醛的反应,考察了催化剂种类、反应条件对苯甲醇氧化的影响.实验结果表明,在无任何溶剂的情况下,Zn取代的Keggin型磷钨四丁基铵盐具有最佳的催化活性,反应时间仅为30 min,苯甲醇的转化率可以达到95.6%,苯甲醛的选择性达到了96.4%.在对杂多酸季铵盐结构的研究基础上,对可能的反应机理进行了初步探讨.

Solvent-Free Selective Oxidation of Benzyl Alcohol to Benzaldehyde Catalyzed by Zinc Mono-Substituted Phosphotungstic Acid Quaternary Ammonium Salt

A series of Zn-substituted Keggin phosphotungstic acid quaternary ammonium salt catalysts were prepared, and characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD). Their catalytic activities were evaluated by the oxidation of benzyl alcohol to benzaldehyde with H2O2 under solvent-free conditions. The effects of reaction parameters on the oxidation of benzyl alcohol were also investigated in detail. All the catalysts show good catalytic activity with fast reaction rate, eco-friendly and excellent selectivity for the desired products. In the absence of any solvent, the conversion of benzyl alcohol and the selectivity of benzaldehyde were found to be as high as 95.6% and 96.4% under optimum conditions in just 30 min. And a possible reaction mechanism of the oxidation of benzyl alcohol was deduced.