固载离子液体刷/过氧磷钨酸盐催化剂催化H2O2选择性氧化硫醚

以二氧化硅为载体,合成了一种新型的双层离子液体刷固载过氧磷钨酸盐催化剂.采用元素分析、IR和SEM-EDAX等手段对催化剂进行了表征.室温下,考察了该催化剂催化30％(质量分数)H2O2溶液选择性氧化硫醚为亚砜或砜的催化性能.结果表明,该催化剂具有很高的催化活性和选择性.采用1.1倍H2O2时,反应选择性地生成亚砜,仅...

Selective Oxidation of Sulfides with Hydrogen Peroxide Catalyzed by Supported Ionic Liquid Brush/Peroxo Phosphotungstate

A heterogeneous catalyst composed of peroxotungstates immobilized on bis-layered ionic liquid brush-modified silica has been synthesized and characterized by elemental analysis, IR and SEM-EDAX. The catalytic property of the system was examined for the oxidation of sulfides to sulfoxides or sulfones with 30% hydrogen peroxide at room temperature. The results showed that this recoverable catalyst exhibited both high catalytic activity and excellent selectivity. The sulfides were selectively oxidized to sulfoxides with traces of sulfones using 1.1 times of H2O2. Changing the amount of H2O2 to 2.5 times, sulfones were given as the main products. It is noteworthy that the catalyst afforded high chemoselectivity towards sulfur groups with unsaturated double bonds even though excess hydrogen peroxide was used. There was no apparent loss of catalytic efficiency through seven cycles.