Basic activity of Y zeolite containing alkylammonium cations in Knoevenagel condensation

This paper compares the catalytic activity of Y zeolite containing alkylammonium cations in the Knoevenagel condensation. For steric reasons, the exchange of Na+ for alkylammonium cations was restricted to the faujasite supercavity, and the degree of ion exchange decreased with the radius of the organic cation. The basicity of the catalysts was analyzed using X-ray photoelectron spectroscopy (XPS) and the Knoevenagel condensation reaction, with good correlation obtained between the results of the two methods. The best catalytic activity was observed for the Y zeolite exchanged using the butylammonium cation. The better performance of this catalyst was attributed to increased accessibility of the reactants to the catalytic sites.