ZrO2催化无溶剂条件下醇的液相氧化反应

采用一种环境友好的方法,以分子氧为氧化剂,以ZrO2为催化剂,在无溶剂的条件下实现了醇的选择性氧化.苯甲醛、环己酮和辛醛等是相应醇的主要氧化产物.考察了不同反应条件(搅拌速度、反应时间和温度)、催化剂制备参数(焙烧温度和负载量)及氧分压等的影响.结果发现,对于醇氧化生成相应羰基化合物,1 223 K焙烧的ZrO2比723 K焙烧的ZrO2显示出更高的催化活性.催化剂在反应混合物中不溶解,可以通过简单的过滤使其分离并重复使用.当搅拌速度大于900 r/min时,对醇的转化速率无明显的影响.

Liquid-Phase Oxidation of Alcohols Catalyzed by ZrO2 under Solvent Free Conditions

The selective oxidation of alcohols,in an environmental friendly protocol,was carried out under solvent free conditions using molecular oxygen as the oxidant and ZrO2 as the catalyst.Benzaldehyde,cyclohexanone,and octanal were the major products from their respective alcohols.The influence of different reaction parameters(speed of agitation,reaction time,and temperature),catalyst parameters(calcination temperature and loading),and oxygen partial pressure on the catalyst performance was studied.ZrO2 calcined at 1 223 K was found to be more active than the one calcined at 723 for the alcohol oxidation to the corresponding carbonyl products.The catalyst is insoluble in the reaction mixture and can be easily separated by simple filtration and reused.The agitation speed beyond 900 r/min show no significant effect on the rate of conversion.