稻壳二氧化硅负载铁催化剂对苯酚双氧水羟化反应的催化活性

Catalytic Activity of Iron-Rice Husks Silica Catalyst on Hydroxylation of Phenol with Hydrogen Peroxide

利用稻壳热解法制备出无定形二氧化硅(Rice Husks Silica,RHS),以其为载体,通过浸渍法制得负载铁催化剂Fe3+/RHS,并将该催化剂用于催化苯酚双氧水直接羟基化反应。研究了催化剂的具体制备条件,反应时间、反应温度和催化剂用量对催化反应效果的影响。HPLC对苯酚双氧水羟基化反应的结果进行监测。结果表明:当m(苯酚)=1.88g,n(苯酚)∶n(H2O2)=1∶1,溶剂为10mL水时,催化剂(Fe3+/RHS)最佳用量为30mg,反应最佳温度为65-70℃,反应结束时间为60min。在相同反应条件下,该负载铁催化剂对苯酚羟化反应的催化效果优于其他几种催化剂。

White amorphous silica powder（RHS） was prepared by thermal decomposition of Rice Husk（RH）.Iron silica catalysts（Fe3＋/RHS）were prepared by means of a simple solvent dipping technique.The effects of reaction time,temperature and catalyst amount for hydroxylation of phenol with hydrogen peroxide were explored,and catalytic reaction was monitored by HPLC.The results suggested that the best reaction conditions found in this work to obtain high yield of catechol and hydroquinon were：catalyst amount was 30 mg,reaction temperature was 65-70 ℃ and complete reaction time was 60 min.When phenol dosage was 1.88 g,molar ratio of phenol and H2O2 was 1,water volume was 10 mL.Fe3＋/RHS showed better catalytic activity on hydroxylation of phenol than that of others.