Promising material for large-scale H2 storage and efficient H2-CO2 separation

Hydrogen is a clean energy source which can replace fossil fuels in a hydrogen economy, thereby drastically mitigating climate change. However, hydrogen storage – due to the high volatility of hydrogen – and H2-CO2 separation (a key requirement in the industrial hydrogen production) are currently the main obstacles in implementing such a hydrogen economy. We thus developed an advanced material which is highly efficient in terms of H2 storage, but also H2 separation fom CO2 streams. We thus modified sub-bituminous coal by incorporating different concentrations of nano-sized CaO nanofluid into the coal. The raw and modified coals (sub-bituminous-1, sub-bituminous-2 and sub-bituminous-3) were characterized and tested for their hydrogen storage capacity and H2-CO2 separation efficiency. Indeed, sub-bituminous-2 reached a very high H2 adsorption capacity (up to 0.866 mol.kg−1) and clearly can therefore store large quantities of H2. In addition, sub-bituminous-3 demonstrated excellent H2-CO2 separation efficiency (CO2-H2 adsorption selectivities of up to 4.1 were measured). This work therefore illustrates new highly cost-effective and technically efficient materials for H2 storage and H2 production, thus aiding in the industrial-scale implementation of a hydrogen economy.