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日用化学工业 ›› 2022, Vol. 52 ›› Issue (4): 396-403.doi: 10.3969/j.issn.1001-1803.2022.04.008

• 开发与应用 • 上一篇    下一篇

磁性固体酸催化剂Fe3O4/C-SO3H制备及表征

喻红梅,华平*(),李建华,钱锋   

  1. 南通大学 化学化工学院,江苏 南通 226000
  • 收稿日期:2021-06-25 修回日期:2021-03-25 出版日期:2022-04-22 发布日期:2022-04-25
  • 通讯作者: 华平

Preparation and characterization of magnetic solid acid catalyst Fe3O4/C-SO3H

Yu Hongmei,Hua Ping*(),Li Jianhua,Qian Feng   

  1. College of Chemistry and Chemical Engineering, Nantong University, Nantong, Jiangsu 226000, China
  • Received:2021-06-25 Revised:2021-03-25 Online:2022-04-22 Published:2022-04-25
  • Contact: Ping Hua

摘要:

以四氧化三铁为磁核,生物质碳(葡萄糖、淀粉、蔗糖)为原料,采用先制备Fe3O4/C,再对其进行磺化的方法制备磁性碳基固体酸催化剂Fe3O4/C-SO3H。以辛基葡萄糖苷的合成反应为探针,考察生物质碳种类、碳化温度、碳化时间、酸种类、磺化温度和磺化时间等因素对葡萄糖转化率和催化剂酸含量的影响。利用FT-IR、XRD、TG、SEM和振动样品磁强计(简称VSM)等对催化剂进行表征。结果表明Fe3O4/C-SO3H的最佳制备条件为:以淀粉为生物质碳源,其用量为m(Fe3O4):m(淀粉)=1:10,碳化温度为190 ℃,碳化时间为8 h,以对甲苯磺酸为磺酸源,其质量比为m(Fe3O4/C):m(对甲苯磺酸)=1:0.6,磺化温度为250 ℃,磺化时间为4 h。在上述条件下,催化剂酸含量为1.17 mmol/g,葡萄糖转化率为97.9%。表征结果也表明,具有良好晶型结构的Fe3O4在后续的碳化和磺化过程中,结构没有发生明显的变化,仍保留着良好的磁学性能。催化剂Fe3O4/C-SO3H具备一定的孔道结构,热稳定性能良好。

关键词: 磁性催化剂, 固体酸催化剂, 辛基葡萄糖苷

Abstract:

Fe3O4/C-SO3H was a magnetic carbon-based solid acid catalyst. It was prepared with Fe3O4, biomass carbon and sulfonic acid source, in which Fe3O4 was the magnetic core and biomass carbon (glucose, starch, sucrose) was the raw material. Firstly, Fe3O4/C was prepared by the carbonization reaction taken place between Fe3O4 and biomass. Then, sulfonation of Fe3O4/C with p-toluenesulfonic acid was carried out, and thus Fe3O4/C-SO3H was prepared. The synthesis of octyl glucoside was used as a probe reaction. The activity of the catalyst was measured by the conversion of glucose and the catalyst acid content. The influencing factors such as biomass carbon type, carbonization temperature, carbonization time, acid type, sulfonation temperature and sulfonation time were investigated. The catalyst was characterized by FT-IR, XRD, TG, SEM and Vibrating Sample Magnetometer (VSM). The results show that, the optimum preparation conditions of Fe3O4/C-SO3H are as follows: Starch is the best biomass carbon source among glucose, starch and sucrose; the mass ratio of Fe3O4 to starch is 1:10; carbonization temperature is 190 ℃; carbonization time is 8 h; among the three sulfonic acid sources (p-toluenesulfonic acid, dodecylbenzene sulfonic acid and concentrated sulfuric acid), p-toluenesulfonic acid is the best; the mass ratio of Fe3O4/C to p-toluenesulfonic acid is 1:0.6; the sulfonation temperature is 250 ℃; the sulfonation time is 4 h. Under the optimized conditions, the acid content of the catalyst is 1.17 mmol/g, and the glucose conversion is 97.9%. XRD results show that the crystal structure of magnetic Fe3O4 particles does not significantly change after carbonization and sulfonation, and the catalyst still retains good magnetic properties. FT-IR analysis shows that sulfonic groups are successfully loaded on the carrier Fe3O4/C. Thermogravimetric analysis shows that Fe3O4/C-SO3H has good thermal stability below 300 ℃. SEM shows that magnetic Fe3O4 particles are irregular spherical particles with uniform size distribution and agglomeration. After carbonization, Fe3O4 are encapsulated by starch, and the particle size becomes larger, and there is a certain pore structure. The Fe3O4/C-SO3H catalyst also has a certain core-shell structure, and the particle size is approximately 30 nm. The VSM curves show that the magnetic strength of Fe3O4/C and Fe3O4/C-SO3H is much smaller than that of Fe3O4, but Fe3O4/C-SO3H can be separated from the system rapidly by simple magnetic attraction. It shows that the final magnetic properties of Fe3O4/C-SO3H meet the requirements of magnetic separation and recovery.

Key words: magnetic catalyst, solid acid catalyst, octyl glucoside

中图分类号: 

  • TQ423