Surface functionalization of zeolitic catalysts as a strategy to eliminate the use of solvents and increase in stability for liquid-phase reactions

Abstract

In the current context, in which there is a constant search for alternatives to fight or at least, curb the environmental imbalance, "synthetic chemistry" is subjected to a great demand for techniques that substitute the need for homogeneous catalysts, mainly organic solvents. In order to supply these needs, acid heterogeneous catalysts have been having an increasing relevance in chemical processes, such as the cracking and refining of petroleum. Even though having great potential, basic heterogeneous catalysts haven't had the same applications as the acid ones, for this reason, this project proposes the development of basic catalysts, for the evaluation of their catalytic activity when applied to Knoevenagel condensation reactions. This reaction is largely used for the production of chemical intermediates during the production of cosmetics and is processed in the presence of organic solvents at high temperatures, to improve the reaction's yields. That way, we plan to produce zeolites of faujasite structure (FAU), functionalized with organosilanes to improve the hydrophobicity of the structure and approximate the reactive liquid phases of the active site, eliminating the use of solvents. From that, we also intend to analyze the stability of the functionalized zeolite in high temperatures liquid systems, because in normal conditions, zeolites of the FAU type present degradation of their structure and decrease in their catalytic activity when in contact with hot water, which can be attenuated with the increase in hydrophobicity as a result of the functionalization.(AU)