Investigação das propriedades catalíticas da MOF URJC-1 ― uma abordagem DFT

Abstract

In 2016, Leo et al. published their work on the synthesis, characterization and study of the catalytic properties of MOF URJC-1. Its material was tested against the Knoevenagel condensation reaction between benzaldehyde and malononitrile. Their results were compared to the other two MOF's, with URJC-1 being the one that showed the best ability to catalyze this reaction. Thus, this work was conceived so that, based on theoretical-computational methodologies, a more in-depth study of the physical and chemical processes involved in the reaction of the bulk of URJC-1 could be carried out, with the main objective of investigating the physicochemical properties which make this material a good catalyst for Knoevenagel condensation. The studies started from the investigation of the processes involved in the non-catalyzed reaction, which resulted in evidence that reinforces the importance of solvents and catalysts used in these reactions. The ability of a tertiary amine to catalyze this reaction was also verified, since the behavior of the basic nitrogen sites present in the pores of URJC-1 may be similar to those observed for a tertiary amine. Condensed-phase studies for the Knoevenagel reaction and condensation in the URJC-1 bulk provided crucial evidence to state that the reaction between benzaldehyde and malononitrile takes place on the external surface of the catalyst, but even so, the model must be adjusted so that this result is factual. Studies were also carried out with two fragments of the pores of the URJC-1, composing an approximate model so that the reaction processes could be studied molecularly. Despite not correctly describing the experimental data, the approximations allowed the design of another possible reaction path for the Knoevenagel condensation in the URJC-1 bulk, which is a mechanism that can be better investigated in the future.