This work aims to study the activation of Tunisian smectite clay with sulfuric acid and to investigate the catalytic role of the sulfuric acid adsorbed onto its surface in the stearic acid esterification by ethanol. The structural modifications brought to the clays after activation have been identified by X-ray diffraction (XRD) and Infrared spectroscopy (IR). The chemical analysis by microanalysis X (MX) reveals the presence of the sulfuric acid adsorbed onto clays surface after activation. It has been shown that these clays, used as catalysts for esterification of stearic acid with ethanol, show two types of catalytic activities. A catalytic activity of surface related to the cationic exchanges and another important related to the sulfuric acid adsorbed onto clay surface. These catalysts show a high stability allowing them to be used several cycles with a sufficient activity.
S. Bouguerra Neji, M. Trabelsi, M.H. Frikha
Activation, Adsorption, Sulfuric acid, Smectite, Esterification