Synthesis, characterization, and novel reactivity of nano CeO2 catalyst for solvent-free Knoevenagel condensation

Abstract

We synthesized the nano CeO₂ using the sol-gel method and characterized the material using different techniques, including XRD, FT-IR, BET surface area, SEM, and TEM analysis. We tested the catalytic functionalities of nano CeO₂ catalyst for Knoevengel condensation of different substituted benzaldehydes with malononitrile, which offered exceptional 95 % conversion and yield. The results support that nano CeO₂ material significantly boosted the yield of the desired product compared to the bulk material. The low-angle XRD profile showed that the regenerated nanomaterial fully retained the porous nature and cubic structure of ceria. FT-IR results reveal that the characteristic vibrational IR band is at 720 cm⁻¹, which is attributed to Ce–O–Ce stretching. The BET surface area result indicates that nano-ceria possesses a higher surface area than bulk CeO₂ material. The SEM analysis illustrates cube-like morphology and TEM data show the nanorod-like appearance of ceria. The nanocatalyst exhibited stable and sustainable activity during regeneration up to 5 cycles.