中文摘要：

以超临界二氧化碳（scCO2）/聚乙二醇（PEG）两相为反应介质,双齿氮配体功能化聚乙二醇稳定的Pd纳米颗粒作为催化剂,进行了醇的需氧氧化反应.系统研究了催化剂制备条件和反应条件对苯甲醇需氧氧化反应的影响.结果表明,以氢气为还原剂制备的Pd纳米粒子的催化活性最高.反应结束后,可以利用scCO2直接进行原位萃取得到产物,实现了催化剂与产物的有效分离和催化剂的循环使用.反应中没有检测到钯的流失.催化剂经过5次循环利用后转化率仍可达98%.

英文摘要：

The aerobic oxidation of various alcohols to the corresponding aldehydes or ketones was carried out using stabilized palladium nanoparticles in a supercritical carbon dioxide （scCO2）/poly（ethylene glycol） （PEG-2000） biphasic system. The effects of reaction conditions on catalytic activity were investigated in detail. Among the Pd nano-catalysts reduced with different reductants, Pd nanoparticles obtained by H2 reduction showed the best catalytic performance in the oxidation of benzyl alcohol. The products can be easily extracted with scCO2 in situ from the Pd nano-catalyst immobilized in functionalized poly（ethylene glycol）, and therefore the loss of palladium could be eliminated. The conversion reached 98% after the catalyst was reused 5 times.