Synthesis and characterization of B-substituted nanoporous carbons with high energy of hydrogen adsorption.”

International audienceThe systematic usage of fossil fuels and the emission of their combustion products (mostly CO2) in the air have already impacted global climate. Therefore, new technological solutions to drug the global energy economy towards cleaner and renewable fuels, in particular for mobile applications, are urgently needed. In particular the efficient storage of hydrogen, a clean energy vector, requires to develop an adequate sorbent operating at ambient temperature and moderated pressures, with simultaneously optimized specific surface and hydrogen binding energy. In this project we explore the potential effectiveness of arc-discharge procedure to synthesize carbon-based nanoporous sorbents with characteristics fulfilling the requirements of vehicular applications. We show that by adjusting the synthesis parameters is possible to prepare numerous graphene-based structures of different forms, sizes, and interconnections between them. The arc-discharge technique provides also a relatively easy way to incorporate heteroatoms (like boron or nitrogen) into pure carbon structures. The as-synthesized boron-substituted carbon nanostructures are characterized in term of texture (using nitrogen adsorption and spectroscopic measurements) and homogeneity of boron (using energy filtered transmission electron microscopy). The calorimetric study at different temperatures were performed to quantify the material’s capacity to adsorb hydrogen.The obtained results are promising. The energy of hydrogen adsorption in our samples is the highest ever observed experimentally in carbon-based sorbents. However, the specific surface of as prepared samples is low. Therefore, the thermal and chemical activation procedure have been applied to increase the surface accessible for adsorption and micropore volume, and in consequence, the samples’ capacity to store hydrogen