The NanoComposites for Active Gas Encapsulation (nanoCAGE) project will deliver smart composite materials to address the problem of safe and efficient hydrogen storage. As a future replacement for fossil fuels, hydrogen is a promising low-carbon, renewable energy carrier, but as a low-density gas it is challenging to store on board a vehicle. Nanoporous materials (materials containing holes only a few nanometers in diameter) have been shown to spontaneously adsorb hydrogen so that it can be stored at exceedingly high densities under the right conditions. However, storage of industrially relevant amounts of hydrogen (i.e. at levels approaching US Department of Energy technical targets) via adsorption in porous materials necessitates storage at very high pressures (typically >350 bar) or very low temperatures (e.g. 77 K). The work described here challenges conventional approaches to the development of porous materials for storage of hydrogen which rely on simple adsorption of gases onto materials surfaces, and instead will change the mechanism by which the hydrogen is stored. These new composites will be based on encapsulating existing nanoporous adsorbents in a continuous matrix of an active material that can control when gases are allowed in or out of the pores of the adsorbent. The novel approach is that the active components will be triggered to undergo a reversible change in structure to induce controlled and reversible pore blocking to either allow or obstruct the movement of gases to or from the pores of the adsorbent, allowing these materials to act as a "nanocage" for gas molecules. Another key innovation of the nanoCAGE project is the introduction of control over the trapping and release mechanisms using changes in external conditions such as light, heat or application of a magnetic field to change the structure of the active phase. This approach, building upon the PI's expertise in hydrogen densification in nanoporous materials, could increase the amount of hydrogen stored in these materials at room temperature by ten times, making economical storage of hydrogen possible and providing a gateway to use of hydrogen for sustainable energy applications. This will accelerate the adoption of non-polluting hydrogen fuel cell vehicles and will lead to benefits to the UK in terms of improved air quality, reduced carbon emissions and decreased reliance on imports of fossil fuels. These composite materials could furthermore find application in many other fields of research (for example in carbon dioxide capture, controllable drug delivery and smart packaging) and will allow the PI to develop an exciting new research area in active gas trapping composites.

The research area of porous materials is extremely diverse, including inorganic materials, organic polymers, synthetic frameworks, biological tissues and composite systems. The variety of applications is equally wide ranging, including renewable energy, separation processes, carbon capture, catalysis, water purification, electronic materials and medicine. This requires combined expertise across multiple science and engineering disciplines, and access to specialist characterisation facilities to study both pore sizes and phenomena that can span multiple scales. A single institution cannot cover the full range of expertise, facilities and applications and a combined effort is therefore required. The EPSRC Network in Engineering Porous Materials at Multiple Scales (EPoMM) therefore aims to foster multiscale and applications- led collaboration between scientists and engineers that spans the entire engineering and physical sciences portfolio. These collaborations will inspire new research directions and new applications to achieve globally significant outcomes with academic, commercial and societal benefits. The vision of the ESPRC Network for Engineering Porous Materials at Multiple Scales (EPoMM) is to make the UK an internationally recognised beacon for multiscale porous materials research, where new collaborations are formed, new research directions are identified, expert advice can be sought, and innovations are commercialised.