Probing the EXOTIC properties of gas and ions filled ICES under extreme conditions: planetary interiors modelling and gas storage applications – EXOTIC-ICES

All models of the interiors of ice bodies in the Universe rely on our knowledge of the behaviour of a few simple molecules—hydrogen, water, methane, ammonia, nitrogen, helium —under high pressure (p) and temperature (T). In the last two decades, a tremendous effort has been devoted worldwide to determine the phase diagram of these systems up to extreme p-T conditions, a research to which members of our team have given key contributions. With these data at hand, and with the information obtained from various spectacular space missions, the scientific community is currently trying to understand the interior of ice bodies, their thermodynamic conditions, their chemistry, and ultimately the possibility to host life therein. Furthermore, several fundamental - and sometime unexpected- discoveries have been derived from these high p-T studies, among them: metallization of hydrogen, quantum criticality, high Tc superconductivity, polyamorphism, superionicity.
Our team has recently shown that solid water under pressure can unexpectedly accommodate substantial amounts of guest species, like ions or small gas molecules, in its lattice. The inclusion of guest species strongly modifies the density, structural, thermal, and conductivity properties of ice, and promotes novel states of matter and remarkable properties. The existence of these “filled ices” in extra-terrestrial bodies challenges our present description of their physics, essentially based on the assumption of the properties of pure ice.
Filled ices also show an incredibly enhanced capability of gas storage and sequestration with respect to common hydrates. Their potential as hydrogen storage materials and natural gas reservoirs, as well as their possible application for CO2 sequestration urgently need to be explored.
The ultimate goal of our project is to define the range of existence of astrophysically relevant ion and gas “filled ice” structures, characterise the kinetics of their formation, unravel their unusual dynamical and conductivity properties under extreme p-T conditions, promote their stability at industrial exploitable conditions, and tailor their future applications as hydrogen storage and CO2 sequestration materials. This aspect of the proposed research perfectly matches the goals of the European Green Deal, as well as those of the PNRR, where hydrogen is looked upon as the next-generation clean-energy carrier.
To realise our project we will combine complementary ground-breaking experimental techniques and novel simulation methods developed by our team of experts in the physics of molecular materials at extreme conditions and planetology.