REVERSIBLE H2 storage via BCN – REVERSIBLE

The porous materials based on light atoms (boron, carbon and nitrogen) mentioned above were developed via a bottom-up approach including the production of molecules based on boron, carbon and nitrogen (amine-boranes), their structuring at scale, their polymerization at temperatures close to 100°C, and finally their pyrolysis at temperatures above 500°C in order to produce porous materials known as BCN. This is how we developed a series of new molecules for the first step of our approach and a series of new (very) porous BCN materials for the last step. All these new compounds were finely analyzed using all the relevant techniques at our disposal, and the porous BCN materials were finally tested for the storage of hydrogen in particular.

The REVERSIBLE project produced several new molecules, amine-boranes with carbon chains, which allowed us to better understand their physicochemical properties, to highlight the importance of the weak dihydrogen bond existing between molecules, and to explore their potential to produce porous C-doped BCN and BN materials. Indeed, more than ten porous C-doped BCN and BN materials have been produced, analyzed, and tested. Although not very effective in storing hydrogen, these materials have shown remarkable performance in the adsorption of carbon dioxide, opening up new prospects for development in an environmental context of reducing emissions of this gas.

BCN materials are able to adsorb and store hydrogen, however, this is only effective at low temperatures, i.e. -196°C as for all porous materials in development today. Prospects for application in this field remain open provided that the porosity is considerably increased. BCN materials are, at this stage, much more promising for the capture of carbon dioxide at room temperature. This therefore opens up development prospects in a sensitive field and these materials could, in the future, be further studied and optimized to participate in the reduction of carbon dioxide emissions.

The research carried out within the framework of this collaborative project has enabled us to develop our knowledge and acquire new information on amine-boranes and porous C-doped BCN and/or BN materials. To date, we have shared our results with the scientific community through 6 scientific articles published in international and recognized journals and through 8 presentations at national and international congresses. Through these actions, we have positioned ourselves, on a global scale, as leaders in this field of research.

This is a collaborative research project involving 2 partners who have already demonstrated their complementary and a synergetic cooperation in the frame of a preliminary work that resulted in a proof of concept as well as in the present proposal. Ammonia borane (AB) nanoparticles were successfully synthesized with one of its derivatives (an amine-borane adduct, ABA) used as surfactant, and such new AB@ABAs nanostructures open new perspectives for elaborating porous BCN materials by means of controlled heat-treatment. BCN materials have been computationally designed, in the recent years, as attractive solutions for reversible H2 storage at ambient conditions. However, there is no experimental evidence yet. The present ambitious project aims at confirming the potential as well as a breakthrough in the field of reversible H2 storage. Accordingly, the project addresses the ANR’s challenge B2 and fits in the axis 1.5 dedicated to e.g. “hydrogen and fuel cells”.