竹炭基固体磺酸催化剂的制备及其催化合成癸二酸二丁酯性能研究

PREPARATION AND PERFORMANCE OF SULFONATED CHARCOAL-BASED SOLID ACID CATALYST FOR SYNTHESIS OF DIBUTYL SEBACATE

以竹材为原料、氯磺酸为磺化剂,通过炭化-磺化法制备竹炭基固体磺酸催化剂,采用傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、扫描电子显微镜仪(SEM)及热失重分析(TGA)等手段对催化剂进行表征,并将其用于催化癸二酸与正丁醇的酯化反应,考察制备条件对催化剂活性的影响。结果表明:竹炭基固体磺酸催化剂具有无定形炭结构,其热稳定性良好;合成催化剂的最佳条件为炭化温度325℃、炭化时间1h、氯磺酸与竹炭配比2.5mL/g、室温下磺化2h,在此条件下制得的催化剂含酸量可达到1.77mmol/g;在正丁醇与癸二酸摩尔比为3.0、反应时间为100min、竹炭基固体磺酸催化剂用量为癸二酸质量的2.0%、环己烷用量为3mL的条件下,癸二酸转化率达99.14%,重复使用4次后,癸二酸转化率仍可保持在80%以上,说明催化剂性能稳定,具有良好的循环使用性能。

A novel charcoal-based sulfonated solid acid was synthesized through carbonation and then sulfonation of the bamboo charcoal using chlorosulfonic acid.The esterification of sebacic acid and n-butyl alcohol was taken as the model reaction to investigate the impact of preparation parameters on the catalyst activity.Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscope(SEM)and thermo gravimetric analysis(TGA)were used to characterize the catalyst.The results show that the charcoal-based solid acid catalyst has amorphous carbon structure and the catalyst prepared at the optimal conditions of carbonization at 325℃for 1hand then sulfonation at room temperature for 2hwith acid-bamboo charcoal ratio of 2.5mL/g exhibits a higher catalytic activity.Its acid amount can reach 1.77mmol/g.The conversion rate of sebacic acid reaches 99.14% at the following conditions:n-butyl alcohol to sebacic acid mole ratio 3.0,the amount of charcoal-based sulfonated solid acid for 2%of sebacic acid,3mL cyclohexane,and reaction time 100min.After repeated use 4times,sebacic acid conversion rate remains above 80%,indicating the good regeneration performance.