(48g) Super-Saturation of Nitrogen and Hydrogen in Transition Metals and Metal Hydrides/Nitrides

Super-saturation of metals with small gas molecules may occur when the amount of dissolved gas exceeds the theoretical maximum solubility at a given temperature and pressure. Since supersaturation effectively increases the amount of gas uptake, it could be useful in material storage and clean energy applications, such as in the case of hydrogen storage or carbon capture. One of the additional consequences of super-saturation is to induce a change in the physical properties of the bulk solid. Super-saturation may possibly enhance small gas diffusivity in metals, a factor that could improve separations in metallic membrane applications. A fundamental understanding of how super-saturation influences material properties can help guide engineers in the design of more effective materials.

The potential for super-saturation-induced property enhancement depends on two factors: (i) in what context is the desired property change considered desirable, and (ii) can super-saturation effectively induce this desired change. Other sub-related concerns involve the stability of this super-saturated state, the reversibility of the induced change, and the energy cost associated with establishing and maintaining the super-saturated state. In order to gain insight into the behavior of super-saturation in metals and related materials, density functional theory is used to investigate the fundamental mechanisms of super-saturation in both pure, alloy and defected (with vacancies) materials.