Efficient conversion of formaldehyde and propanal to methacrolein on ionic liquid-functionalized polymer catalyst

In recent years, the methacrolein (MAL) synthesis through the aldol condensation of formaldehyde (FA) with propanal (PA) has received great attention of researchers. Herein, an ionic liquid-functionalized polymer catalyst, which exhibited higher performance than common homogenous sec -amine catalyst, was developed for catalytic synthesis of MAL via aldol condensation of FA with PA. FT-IR, XPS, TG-DTA, and 13 C MAS NMR were used to characterize the structural and physicochemical features. The influences of solvent and reaction conditions on the catalytic performance were also systematically studied and optimized. The in situ FT-IR spectroscopic experiments were performed to investigate the catalytic mechanism. Kinetic studies revealed that the activation energy of aldol condensation between the FA and PA was 51.6 kJ/mol. No obvious decay of catalytic performance was observed after twelve cycles.