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Amine functionalized solid adsorbents are promising materials for the capture of CO 2 because of their tunability and lower heat capacity compared to liquid amine solutions. This review focuses on recent advances in the use of solid-supported amines for CO 2 capture, with emphasis on amine functionalized metal organic framework (MOF) materials. The recently reported diamine functionalized Mg-DOBPDC MOF demonstrates intriguing performance for CO 2 capture, offering a unique adsorption mechanism with favorable energetics. Stable performance for CO 2 capture under humid conditions and easy regenerability of the adsorbent are critical to the realization of practical CO 2 adsorbents. Scalable regeneration methods such as temperature swing in a CO 2 purge stream and temperature swing via steam stripping are discussed. Emerging gas-solid contacting strategies for CO 2 capture with amine adsorbents are also discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Atomistic modeling techniques for microporous feature analysis. • In silico predictions of adsorption with flexible frameworks. • Data-driven methods are positioned to accelerate PIM discovery and design. Polymers of intrinsic microporosity (PIMs) are a family of materials with potential to be effective and scalable solutions for challenging adsorbent and membrane applications. The broad range of repeat unit chemistry, microporous structural features, and polymer processing makes exploration of the expansive PIM design space inefficient via chemical and materials intuition alone. Computational techniques such as molecular simulations and machine learning can provide a leap in capabilities to address this polymer design challenge and will be central to the future development of PIMs. We highlight recent microporous material studies that arrived at key results by employing computational techniques and provide our perspective on the prospects for in silico design and development of PIMs. [ABSTRACT FROM AUTHOR]

Abstract: One of the most important processes in producing high purity hydrogen is separating hydrogen from a mixture of gas streams. This work looks at intermetallics, stoichiometric compounds of two or more metals, as prospective membranes for these applications. We describe a systematic computational screening approach based on calculation of key properties like solubility, diffusivity and permeability of hydrogen through these materials using quantitatively accurate Density Functional Theory calculations. Solubility was used as a screening parameter and solubility data has been calculated for 78 Pd-based binary intermetallics. Permeability calculations were performed for the shortlisted candidates. After systematically examining all Pd-based intermetallics, no material was found to have higher hydrogen permeability than pure Pd. To investigate the potential influence of hydrogen on the stability of metastable phases, we examined a number of metastable structures of Pd3Mn. Two metastable Pd3Mn phases are stabilized in the presence of hydrogen, but these phases are predicted to have low permeability. We also explored whether an empirical relationship could be found to rapidly predict H solubility in intermetallics using a QSPR approach. Unfortunately, the values calculated using this empirical approach cannot be used to make useful predictions. [Copyright &y& Elsevier]

Abstract: Amorphous metals are interesting candidates as membranes for H2 purification. Identifying materials with high permeability for H2 remains a challenge in this field. We apply recently developed methods that combine first principles density functional theory calculations and statistical mechanics to make predictions of the properties of interstitial H in amorphous metals. Our calculations greatly expand the number of amorphous metals which have been considered as membranes, and predict several materials with promising properties. [Copyright &y& Elsevier]

Abstract: Amorphous metals are interesting candidates for use as H2 purification membranes and also occur in some applications of H2 storage. We have recently introduced methods that combine first principles density functional theory calculations and statistical mechanics to make predictions of the properties of interstitial H in amorphous metals. In this paper, we apply these methods to investigate H solubility, diffusivity and permeability in amorphous Zr36Ni64 and Zr30(Ni0.6Nb0.4)70, two materials for which experimental data is available. Our calculations, which require no experimental input, agree well with the available experimental data, indicating that our methods can make reliable predictions about performance of amorphous metal membranes for hydrogen purification. [Copyright &y& Elsevier]

Abstract: Many phenomena can occur when chiral molecules adsorb on solids. Density Functional Theory calculations have provided information that strongly complements experimental studies. Advances have been made in two related avenues for creating surface chirality: adsorption of modifiers on achiral surfaces and adsorption on intrinsically chiral metal surfaces. [Copyright &y& Elsevier]

Abstract: We have used atomically detailed methods to examine the surface resistances associated with single-component permeation of CH4, CF4, and C2H6 through single crystal silicalite membranes. Dual control volume grand canonical molecular dynamics (DCV-GCMD) simulations can be used for this purpose, but only for extremely thin membranes and for relatively rapidly diffusing species. We use calculations of this type to introduce a more computationally efficient but approximate method for describing surface resistances, the local equilibrium flux method (LEFM). Using LEFM calculations, it is possible to accurately and rapidly predict surface resistances for large ranges of membrane operating conditions. Using this approach, we identify the crystal thicknesses beyond which surface resistances are negligible for single-component permeation of CH4, CF4, and C2H6 through silicalite membranes as functions of membrane feed and permeate pressure. [Copyright &y& Elsevier]

Abstract: Density functional theory (DFT) calculations have become a valuable complement to experimental methods for studying the structures and dynamics of H in metal hydrides. This article gives an overview of applications of DFT to the diffusion of H and its isotopes in metals, including pure metals, ordered alloys, and disordered alloys. Several examples are used to illustrate how DFT can be used to predict hopping rates due to activated transport and due to tunnelling using methods that can be applied to large numbers of distinct interstitial sites. The application of DFT to examples where clustering of interstitial H atoms occurs such as Sc is also described. [Copyright &y& Elsevier]