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Register a new userPerformance-based screening of porous materials for carbon capture
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Computational screening methods have been accelerating discovery of new materials and deployment of technologies based on them in many areas from batteries and alloys to photovoltaics and separation processes. In this review, we focus on post-combustion carbon capture using adsorption in porous materials. Prompted by unprecedented developments in material science, researchers in material engineering, molecular simulations, and process modelling have been interested in finding the best materials for carbon capture using energy efficient pressure-swing adsorption processes. Recent efforts have been directed towards development of new multiscale and performance-based screening workflows where we are able to go from the atomistic structure of an adsorbent to its equilibrium and transport properties for gas adsorption, and eventually to its separation performance in the actual process. The objective of this article is to review the current status of these emerging approaches, explain their significance for materials screening, while at the same time highlighting the existing pitfalls and challenges that limit their application in practice and industry. It is also the intention of this review to encourage cross-disciplinary collaborations for the development of more advanced screening methodologies. For this specific reason, we undertake an additional task of compiling and introducing all the elements that are needed for the development and operation of the performance-based screening workflows, including information about available materials databases, state-of-the-art molecular simulation and process modelling tools and methods, and the full list of data and parameters required for each stage.
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Shock wave reaction results in various characteristic regimes in porous material. The geometrical and topological properties of these regimes are highly concerned in practical applications. Via the morphological analysis to characteristic regimes with high temperature, we investigate the thermodynamics of shocked porous materials whose mechanical properties cover a wide range from hyperplasticity to elasticity. It is found that, under fixed shock strength, the total fractional area $A$ of the high-temperature regimes with $T geq T_{th}$ and its saturation value first increase, then decrease with the increasing of the initial yield $sigma_{Y0}$, where $T_{th}$ is a given threshold value of temperature $T$. In the shock-loading procedure, the fractional area $A(t)$ may show the same behavior if $T_{th}$ and $sigma_{Y0}$ are chosen appropriately. Under the same $A(t)$ behavior, $T_{th}$ first increases then decreases with $sigma_{Y0}$. At the maximum point $sigma_{Y0M}$, the shock wave contributes the maximum plastic work. Around $sigma_{Y0M}$, two materials with different mechanical properties may share the same $A(t)$ behavior even for the same $T_{th}$. The characteristic regimes in the material with the larger $sigma_{Y0}$ are more dispersed.
Porous carbonaceous materials have many important industrial applications including energy storage, water purification, and adsorption of volatile organic compounds. Most of their applications rely upon the adsorption of molecules or ions within the interior pore volume of the carbon particles. Understanding the behaviour and properties of adsorbate species on the molecular level is therefore key for optimising porous carbon materials, but this is very challenging owing to the complexity of the disordered carbon structure and the presence of multiple phases in the system. In recent years, NMR spectroscopy has emerged as one of the few experimental techniques that can resolve adsorbed species from those outside the pore network. Adsorbed, or in-pore species give rise to resonances that appear at lower chemical shifts compared to their free (or ex-pore) counterparts. This shielding effect arises primarily due to ring currents in the carbon structure in the presence of a magnetic field, such that the observed chemical shift differences upon adsorption are nucleus-independent to a first approximation. Theoretical modelling has played an important role in rationalising and explaining these experimental observations. Together, experiments and simulations have enabled a large amount of information to be gained on the adsorption and diffusion of adsorbed species, as well as on the structural and magnetic properties of the porous carbon adsorbent. Here, we review the methodological developments and applications of NMR spectroscopy and related modelling in this field, and provide perspectives on possible future applications and research directions.
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