【作者】 唐思；

【导师】 杨晓梅； 周利鹏；

【作者基本信息】 郑州大学 ， 工业催化， 2011， 硕士

【摘要】 醛类化合物催化氧化合成羧酸这类反应无论在有机合成还是在精细化工中都有重要的意义和应用价值。本论文研究了固体磺酸催化过氧化氢氧化醛类化合物生成羧酸的反应体系。该体系在温和的条件下,可以实现醛到羧酸的转化,并且催化剂可以循环使用。论文首先考察以磺酸树脂Amberlyst15催化过氧化氢氧化苯甲醛,结果发现在90℃,反应7 h,催化剂的量为5wt%, H2O2的量为30 mmol (1.5 equiv)时,不使用溶剂,苯甲醛的转化率达到85%,使用乙酸作溶剂时,苯甲酸的分离收率达到95%。应用此催化体系催化其它醛的氧化同样表现出较好的催化活性,有缺电子取代的芳香醛和脂肪醛几乎定量生成相应的羧酸。而且Amberlyst15是可以回收循环使用的催化剂,使用三次后,催化活性只略微降低,但是此催化剂机械强度不高,易破碎成细小颗粒。制备了更稳定的磺化碳材料,考察了碳前体和磺化温度的影响,结果发现以淀粉为原料,在150℃磺化时制备的磺化碳材料催化苯甲醛氧化活性最高,而且引入磺酸基的量最大,为1.0 mmol/g。此催化剂在重复使用一次后,活性略微降低,之后重复使用两次,活性基本不变,表明制备的磺化碳材料是可以循环使用的催化剂。该催化剂也可用于其它醛类化合物的催化氧化,但是相同条件下,催化活性比磺酸树脂略低,可能由于磺酸树脂磺酸基的量大于制备的磺化碳材料。更多还原

【Abstract】 The transformation of aldehydes to carboxylic acids is an important reaction in organic synthesis and fine chemical industry. This thesis studied the oxidation of aldehydes to carboxylic acids using H2O2 as oxidant catalyzed by solid sulfonic acid. This catalytic oxidation system could efficiently transform aldehydes to carboxylic under mild conditions, and the catalyst is recyclable.Firstly the oxidation of benzaldehyde to the benzoic acid catalyzed by sulfonic acid resin Amberlyst 15 using 30% H2O2 as the oxidant was investigated. The conversion of benzaldehyde reached 85% under 90℃for 7 h using 5 wt% Amberlyst 15 and 1.5 equiv H2O2. And the yield of benzoic acid was improved to 95% when acetic acid was used as the solvent. The catalytic system also showed good catalytic activity in the oxidation of other aldehydes. Benzaldehyde derivatives with electron-withdrawing group and aliphatic aldehydes were almost quantitatively converted into their corresponding acids. Amberlyst 15 was an efficient, recyclable heterogeneous catalyst for the oxidation of benzaldehyde to benzoic acid by H2O2, which can be recycled for two times and the activity of the catalyst only decreased a little in the third run. But the mechanical strength of Amberlyst 15 was not high and easy to break into small particles.The more stable solid catalyst-sulphonated carbon materials were prepared. The influence of raw material for carbon and the sulphonated temperature were investigated. It was found that when starch was used as the raw material and the sulphonated temperature was 150℃, the sulphonated carbon materials showed the best catalytic activity and the amount of -SO3H was 1.0 mmol/g. The sulphonated carbon materials can be recycled. The catalytic activity slightly decreased when the catalyst was used for once, then the activity almost unchanged in the following two runs. The catalytic system can also catalyze oxidation of various aldehydes. However, the activity was lower than Amberlyst 15 which maybe result from the amount of-SO3H of sulphonated carbon materials was lower than that of Amberlyst 15.更多还原