Synthesis and characterization of ionic liquid based bifunctional periodic mesoporous organosilica supported potassium carbonate as very efficient nanocatalyst for the Knoevenagel condensation

A novel ionic liquid based bifunctional periodic mesoporous organosilica supported potassium carbonate (BPMO-IL-KCO3) is prepared, characterized and its catalytic efficiency is studied in the Knoevenagel reaction. The BPMO-IL-KCO3 was prepared by chemical attachment of 1-methyl-(3-trimethoxysilylpropyl) imidazolium chloride on an ionic liquid based PMO followed by treatment with potassium carbonate under ambient temperature. This material was characterized with thermal gravimetric analysis (TGA), energy-dispersive X-ray (EDX) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The BPMO-IL-KCO3 was then successfully applied as efficient base catalyst in the Knoevenagel condensation of different aldehydes with ethyl cyanoacetate and gave high to excellent yields of the corresponding coupling products. The catalyst was recovered and reused several times without significant decrease in activity and selectivity. The recovered catalyst was also analyzed with TEM and nitrogen sorption experiment to investigate structural stability and durability of the material under applied conditions. (C) 2016 Elsevier B.V. All rights reserved.