Al-MCM-41 supported phosphotungstic acid: Application to symmetrical and unsymmetrical ring opening of succinic anhydride

Mesoporous Al-MCM-41 (Si/Al = 20) molecular sieve was synthesized hydrothermally and characterized by X-ray diffraction (XRD), nitrogen-sorption studies and 27Al and 29Si MAS-NMR spectroscopies. 10, 20 and 40 wt% phosphotungstic acid (PW) (H3PW12O40) were supported on Al-MCM-41 and the resulting catalysts were characterized by XRD, FT-IR, nitrogen-sorption, DRIFT, 1H and 31P MAS-NMR and DRS UV–vis spectral techniques. 1H MAS-NMR spectra of PW/Al-MCM-41 revealed leveling of the acidity of PW protons to Al-MCM-41. Their catalytic activities were evaluated in the esterification of succinic anhydride with ethanol in the temperature between 60 and 120 °C. Monoethyl succinate (MES) and diethyl succinate (DES) were obtained as products. The effects of alcohol/anhydride molar ratio and temperature were studied. Unsymmetrical alcoholysis of succinic anhydride with methanol and 1-butanol was also carried out successfully.

Al-MCM-41 supported phosphotungstic acid (10, 20 and 40 wt% PW/Al-MCM-41) catalysts were synthesized, characterized and their catalytic activities were evaluated in the esterification of succinic anhydride with ethanol. Monoethyl succinate and diethyl succinate were obtained as products. Unsymmetrical alcoholysis of succinic anhydride with ethanol in the first step and second alcoholysis with methanol and 1-butanol, respectively, yielded methyl ethyl succinate and butyl ethyl succinate as heteroesters. Figure optionsDownload as PowerPoint slide