Abstract:

Immobilized AlCl3 catalyst(AlCl3/ATP) was prepared through solvent refluxing and adsorption method with attapulgite as the support and then used in the synthesis of aspirin. The catalyst was characterized by Fourier transform infrared spectroscopy(FT-IR)， X-ray diffraction(XRD), specific surface area(BET), X-ray energy dispersive spectrometry(EDS) and Hammett indicators. Factors influencing the catalytic properties such as concentration of hydrochloric acid, heattreated temperature, AlCl3 loading and amount of catalyst were optimized according to the yield of aspirin. The catalytic properties of the catalysts and the support were compared before and after loading. The results show that the amount of AlCl3 loading on ATP reached 1.18 mmol/g after ATP acidified with 10 mol/L HCl for 12 h at room temperature and then heat-treated under 300 ℃ for 2 h. The yield of aspirin catalyzed by AlCl3/ATP reaches 92.5% when the dosage of the AlCl3/ATP is 5% mass fraction of salicylic acid, which is higher than that of unloaded AlCl3 and the support itself. The catalyst also exhibits excellent catalytic stability within 5 times reused.

Key words: attapulgite, loading, AlCl3, aspirin, catalytic activity