碳化硅基碳复合核壳固体酸的制备及催化合成苯甲醛-1,3-丙二醇缩醛

以碳化硅粉体为载体,葡萄糖、油酸、腐植酸钠等为碳源,采用水热法炭化及400℃低温炭化获得SiC/C材料,继而气相磺化合成了碳基碳化硅核壳固体酸催化剂。采用XRD、IR、XPS、TG、SEM和TEM对催化剂进行了结构表征,酸滴定法测得其酸度为1.33mmoL/g。以其催化苯甲醛和1,3-丙二醇缩合反应为探针反应测试了其催化活性。考察了原料配比、催化剂用量、反应时间及催化剂重复使用性对缩合产率的影响。结果表明,适宜反应条件为:苯甲醛投料量为0.1mol时,催化剂用量为0.075g,醛醇摩尔比1:1.5,100℃回流2h产率可达83%,该催化剂可以重复使用4次以上。

Preparation of silicon carbide based carbon composite core-shell structure solid acid catalyst for the synthesis of benzaldehyde 1,3-propanediol acetal

The core-shell structure silicon carbide based carbon composite solid acid catalyst was prepared via gas sulfonation progress from SiC/C composites which was synthesized by hydrothermal method and low temperature carbonization at 400℃ using glucose, oleic acid and humic acid sodium as carbon source and silicon carbide as carrier. The catalyst was characterized by XRD, IR, XPS, TG, SEM and TEM. The result showed that the acid value of the solid acid catalyst measured by acid titration method was 1.33mmoL/g. Its catalytic activity was tested by the benzaldehyde and 1, 3-propanediol condensation reaction. Effects of molar ration of raw material, the amount of catalyst, reaction time and reusability of the catalyst on the condensation yield had been investigated. When 0.075g catalyst was used for 0.1 mol benzaldehyde and the molar ration of alcohol to aldehyde in the precursors was equal to 1.5 and the reflux condensation was kept for 2h at 100℃, the condensation yield was 83% and the catalyst could be reused for more than four times.