高岭土载体在杂多钨酸盐催化合成己二酸中的应用研究

以自制杂多钨酸盐K10P2W17O61.13H2O为催化活性组分,高岭土为催化剂载体,H2O2氧化环己酮合成了己二酸,反应完成后分离出负载杂多钨酸盐的高岭土重复循环使用。该合成反应特点是不需反应前制备负载型催化剂,而是利用反应进行的同时催化活性组分即可在载体表面选择性吸附,反应后可方便地将催化活性组分-载体从反应体系中分离出来,并作为催化剂直接重复利用。考察了反应条件对己二酸收率的影响及杂多钨酸盐-高岭土的重复利用催化性能。采用IR分析对杂多钨酸盐、高岭土及杂多钨酸盐-高岭土进行了表征。杂多钨酸盐和载体高岭土第1次用于反应己二酸收率64.4%,分离出的杂多钨酸盐-高岭土逐次重复利用4次,己二酸收率依次为19.7%、20.9%、20.5%和19.2%,表明高岭土对杂多钨酸盐的饱和负载量基本不随重复利用次数增加而减少,有望通过调整杂多钨酸盐-高岭土的再生方法、催化活性组分与载体的比例及用量,达到减少催化活性组分损失及提高产物收率的目的。

Application of Kaolin in Catalytical Synthesis of Adipic Acid with Heteropolytungstate as Catalyst

Adipic acid was synthesized using the self-made heteropolytungstate K10P2W17O61·13H2O as catalytic active component,kaolin as carrier,H2O2 and cyclohexanone as reactants.It was not necessary to prepare supported catalyst before the reaction.Compared with the supported catalyst,this method had the advantages of high specific surface area,ease of separation,decreasing the loss of catalytic active component and lengthening the working life of the catalyst.After the reaction,heteropolytungstate-kaolin separated could be reused.K10P2W17O61·13H2O,kaolin and heteropolytungstate-kaolin were all characterized by IR technique.The yield of adipic acid was 64.4% for the first time.The yields were 19.7%,20.9%,20.5% and 19.2% when heteropolytungstate-kaolin was reused four times successively.The adsorption capacity of heteropolytungstate on kaolin did not reduce with increasing reuse times,showing that it could be psossible to increase the yield and to decrease the loss of catalytically active component by means of changing regeneration method or changing the proportion,of heteropolytungstate and kaolin.