Highly Catalytic Activity of Ba/γ-Ti–Al 2 O 3 Catalyst for Aldol Condensation of Methyl Acetate with Formaldehyde

In this work, titanium-doped mesoporous Al 2 O 3 (γ-Ti–Al 2 O 3 ) was prepared by an evaporation-induced self-assembly method and used as a carrier of Ba/γ-Ti–Al 2 O 3 catalyst to catalyze the aldol condensation of methyl acetate with formaldehyde to methyl acrylate in a fixed-bed reactor. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, N 2 adsorption–desorption, pyridine absorption performed via Fourier transform infrared spectroscope (Py-IR), and NH 3 and CO 2 temperature-programmed desorption (NH 3 and CO 2 -TPD). Experimental results indicated that the doping of the titanium species into the frame work of mesoporous Al 2 O 3 (γ-Ti–Al 2 O 3 ) had a significant influence on the catalytic activity via modifying the acid–base surface properties of the catalyst. Furthermore, the Ba/γ-Ti–Al 2 O 3 catalyst demonstrated excellent catalytic performance, with a methyl acetate conversion rate of 50% and methyl acrylate selectivity up to 90.2%. Compared with the Ba/Al 2 O 3 catalyst, the Ba/γ-Ti–Al 2 O 3 catalyst had better catalytic activity, stability and potential for practical application, which was likely due to an increased number of Lewis acid sites, especially the medium acid sites. Graphical Abstract Barium supported mesoporous γ-Ti–Al 2 O 3 catalyst was found to be an effective catalyst for vapor phase aldol condensation of methyl acetate with formaldehyde.