Enhanced catalysis of mechano-chemically synthesized KMgF3 catalysts for the Knoevenagel condensation

Abstract

Abstract Catalysis of KMgF3 catalysts for Knoevenagel condensation were enhanced by synthesizing mechano-chemically. The BET surface area and number of strongly basic site of KMgF3 were increased by applying greater mechanical energy (higher rotation rate) in a mechano-chemical process. Their increases were caused by stronger mechano-chemical effects such as the micronization of the particles and the creation of lattice defect on the surface, resulted in resulted in the enhancement of catalytic activity of KMgF3 for Knoevenagel condensation. The XPS analysis revealed that the element composition on the surface of KMgF3 was similar with K2MgF4 and indicated the possibility which the true active component for this reaction was K2MgF4 rather than KMgF3. The kinetic measurements revealed that the Knoevenagel condensation catalyzed by KMgF3 was regard as a first order reaction and apparent activation energy was estimated at 55.8 kJmol-1. A soluble component capable of acting as a catalyst was not present in the solution and the KMgF3 acted as a true solid catalyst.