presentation_goncalo_carrera.pdf

           Bio-inspired/Water activated systems for CO2 capture

Gonçalo V. S. M. Carrera, Luis C. Branco, Manuel Nunes da Ponte

LAQV-REQUIMTE / FCT - Universidade Nova de Lisboa

     The work here described consists in the conception and optimization of novel CO2 capture systems involving the employment of carboxylic acids, water, compounds from chiral pool and organic superbases as well. The first prototype combines the use diverse degrees of carboxylic functionalization (formic, malonic, succinic, and citric acids, as examples of sigle, di- and tri-functionalization, and ethylenediamine tetraacetic acid) with the employment of DBU as example of an organic superbase. The prepared carboxylates dissolve in aqueous solution and the carboxyl functionality establishes hydrogen-bond interactions with water, leading to the activation of this molecule for CO2 nucleophilic attack. This reaction leads to hydrogencarbonate and regeneration of the carboxylic acid group. This is a cost effective alternative to conventional CO2 capture systems. The second concept consists on the activation of the amine functionality, from an amino-acid, for CO2 nucleophilic attack, by the presence of an organic superbase. The resulting carbamate can revert back to the initial configuration by heating at the proper temperature. In this work was observed that with the increment of the bulkiness of the substituent group of the a.a. there’s a decrease in the temperature associated to CO2 release from the carbamate. The possibility of use easy available amino-acids in order to tune the energetics of the NC bond of the carbamate and control CO2 release according the demand is envisaged as an interesting system with applicability in diverse situations. The last systems comprise the use of abundant saccharides with organic superbases. The activated alcohol groups perform nucleophilic attack to CO2 leading to organic carbonates. These functionalities can revert back by release of CO2 at moderated temperatures. High CO2 capacity was demonstrated. The use of renewable and cost effective systems characterized by high CO2 uptake, energetic control of CO2 release should constitute valuable frameworks with applicability in real situations.