The Inorganic Perovskite-Catalyzed Transfer Hydrogenation of Cinnamaldehyde Using Glycerol as a Hydrogen Donor

Catalytic transfer hydrogenation reactions (CTHs) produce value-added chemicals in the most economical, safe, green, and sustainable way. However, understanding the reaction mechanism and developing stable, selective, and cheap catalysts has been a significant challenge. Herein, we report on the hydrogenation of cinnamaldehyde utilizing glycerol as a hydrogen donor and metal-oxides (SnO2, LaFeO3, and LaSnO3) as heterogeneous catalysts. The perovskite types were used because they are easy to synthesize, the metal components are readily available, and they are good alternatives to noble metals. The catalysts were synthesized through the nanocasting (hard-template) method with SiO2 (KIT-6) as a template. The template was synthesized using the soft-template (sol-gel) method resulting in a high surface area of 624 m(2)/g. Furthermore, catalytic evaluations gave high cinnamaldehyde percentage conversions of up to 99%. Interestingly, these catalysts were also found to catalyze the etherification of glycerol in one pot. Therefore, we propose competitive surface catalytic reactions driven by the transition metal cations as the binding sites for the cinnamaldehyde and the sacrificial glycerol.

Automated summary

Catalytic transfer hydrogenation reactions offer an economical, safe, green, and sustainable method for producing value-added chemicals. However, developing stable, selective, and cheap catalysts has been a significant challenge. In this study, glycerol was used as a hydrogen donor and metal-oxides (SnO2, LaFeO3, and LaSnO3) were employed as heterogeneous catalysts for the hydrogenation of cinnamaldehyde. Perovskite-type catalysts were chosen for their ease of synthesis, availability of metal components, and potential as alternatives to noble metals. The catalysts were synthesized using a nanocasting method with SiO2 (KIT-6) as a template. The resulting catalysts exhibited high cinnamaldehyde conversion rates of up to 99%, and interestingly, they also catalyzed the etherification of glycerol in one pot.