Aluminium and titanium modified mesoporous TUD-1: A bimetal acid catalyst for Biginelli reaction

Using a simple, non-surfactant template triethanolamine (TEA), bimetal (Al³⁺ and Ti⁴⁺ ions) incorporated mesoporous catalyst AlTiTUD-1 (Si/Al+Ti = 50) was synthesized. The catalyst was characterized by XRD (Low and High angle), N₂ Sorption, FTIR, SEM, TEM, DR UV Visible, and pyridine adsorbed FT-IR techniques. The XRD and N₂ sorption studies confirmed its amorphous, mesoporous nature, which possessed a BET surface area of 590 m² g^-1 and pore diameter of 4.4 nm. The Al³⁺ and Ti⁴⁺ co-ordination within the TUD-1 was evaluated by DR UV-Vis. Pyridine adsorbed FTIR revealed both Bronsted (B) and Lewis (L) acidity, which is responsible for the catalytic activity. The acid catalyst showed a good catalytic performance in Biginelli type multicomponent coupling reaction for the substituted aldehydes, ethyl acetoacetate and thiourea to yield about 70% in reflux condition.