Synthesis of mesoporous SiO2-CeO2 hybrid nanostructures with high catalytic activity for transamidation reaction

Transamidation reactions catalyzed by boronic acid derivatives and metal catalysts are well known nevertheless their requirement for elevated temperatures and long reaction times were considered major obstacles in converting amides to N-alkyl amides with the coupling of primary amides and amines. The acidic-basic co-existence of ceria nanoparticles is considered a perfect choice for different catalytic activities. Mesoporous silica on the other hand is well known for its use as a supporting material for catalysts owing to its excellent characteristics like large surface area, good absorption capacity, and high-temperature stability. The SiO2-CeO2 hybrid nanocomposite was prepared by solvothermal route followed by annealing and the formation of the catalyst was confirmed by XRD, EDX, FTIR, and TEM characterization techniques. The hybrid catalyst shows high catalytic activity towards transamidation reaction at very low temperatures and in solvent-free conditions compared to pure ceria nanoparticles. The SiO2-CeO2 catalyst showed more than 99% selectivity and a remarkable catalytic activity of above 90% for the conversion of N-heptyl amine with acetamide to N-heptyl acetamide at a very low temperature of 120 degrees C for 3 hours. Furthermore, the catalyst remains stable and active for repeated catalytic cycles. It established 80% catalytic activity even after 4 repeated cycles making it suitable for multiple-time usages.

Automated summary

Transamidation reactions catalyzed by boronic acid derivatives and metal catalysts are commonly known and have been hindered by elevated temperatures and long reaction times. The SiO2-CeO2 hybrid nanocomposite, prepared by solvothermal route, exhibits high catalytic activity at low temperatures and solvent-free conditions. It shows over 99% selectivity for the conversion of N-heptyl amine with acetamide to N-heptyl acetamide at 120 degrees C for 3 hours, with above 90% catalytic activity. The catalyst maintains 80% catalytic activity even after 4 repeated cycles.