Nicholas J. Corrente

Understanding the adsorption behavior of hydrogen and deuterium in nanoporous carbons is critical for advancing gas storage and separation technologies. In this study, neutron scattering, gas adsorption, and molecular simulations were combined to unravel the complex interplay between pore structure, spatial confinement, and adsorption mechanisms. By simulating the adsorption in realistic 3D molecular structures of nanoporous carbons, preferred adsorption sites were identified, revealing that highly confining geometries—rich in defects—enhance adsorption. Denser carbons exhibit stronger confinement but lower overall uptake due to limited pore space. Despite accounting for isotope-specific effects, significant deviations between simulated and experimental scattering data suggest distinct molecular arrangements, particularly for H2. The findings of this study underscore the need for refined atomistic models incorporating surface chemistry and spin-isomer effects to bridge the gap between experiment and simulation, guiding the design of optimized nanoporous materials for hydrogen storage.

Recent advances in computational capabilities have revolutionized the modeling of nanoporous carbons, enabling a transition from idealized pore descriptions to versatile three-dimensional molecular models. This review traces the evolution from traditional continuous potential methods and simple pore models to modern simulation techniques that generate realistic carbon structures incorporating surface heterogeneity, pore connectivity, and framework flexibility. We examine various approaches including Hybrid Reverse Monte Carlo, Quench Molecular Dynamics, and Annealed Molecular Dynamics methods, discussing their respective strengths and limitations. Particular attention is given to the choice of interatomic potentials and their impact on structural predictions. The development of million-atom models captures long-range ordering effects previously inaccessible to simulation. Applications of the 3D models demonstrate their ability to quantitatively predict adsorption behavior and provide the improved characterization of practical carbons using novel methods such as 3D-VIS and APDM. Recent hybrid MD/MC approaches, which incorporate the effects of structure flexibility, offer new insights into adsorbate-induced structural changes. This review highlights how advancing computational methods are bridging the gap between molecular-level understanding and practical applications in the carbon materials design and modeling of adsorption processes.

Predicting adsorption-induced deformation in nanoporous carbons is crucial for applications ranging from gas separations and energy storage to carbon capture and enhanced natural gas recovery, where structural changes can significantly impact material performance and process efficiency. The interplay between adsorption and material deformation presents both challenges and opportunities, particularly for CO2–CH4 displacement processes in geological structures where matrix swelling can alter reservoir permeability. We investigate adsorption-induced deformation of nanoporous carbons using an original hybrid Monte Carlo/Molecular Dynamics (MC/MD) simulation approach that couples adsorption sampling with structural relaxation. By studying CH4 and CO2 adsorption on 3D carbon structures of varying densities (0.5–1.0 g/cm3), we demonstrate characteristic non-monotonic deformation behavior, with initial contraction at low pressures followed by expansion at higher pressures. A key contribution is the direct calculation of isothermal compressibility of adsorbate saturated porous structures from the volume fluctuations during NPT-MD simulations, which reveals dramatic mechanical property changes during adsorption. In the process of adsorption, carbon structures exhibit initial softening followed by substantial hardening, with a dramatic increase of the volumetric modulus in denser carbons. Using elastic theory relationships, we estimate the adsorption stresses reaching 175 MPa, that provides crucial insights into potential material degradation mechanisms. For binary CH4/CO2 mixtures, increasing CO2 content amplifies both contraction and expansion effects due to stronger fluid-wall interactions. The iterative MC/MD methodology enables direct observation of the structural evolution and quantitative estimates of the mechanical properties, which are difficult to measure experimentally, advancing our understanding of coupled adsorption-deformation processes in nanoporous materials.

Deformation of nanoporous materials during gas adsorption has been attracting considerable attention due to various applications, including energy and gas storage, carbon capture, and separation. While most practical applications involve multicomponent mixtures, most experimental and theoretical works deal with single-component adsorption. Here, we study the specifics of adsorption-induced deformation during the displacement of methane by carbon dioxide from carbon nanopores, a process of paramount importance for secondary gas recovery and carbon sequestration in shale and coal formations. Density functional theory calculations augmented by the perturbed-chain statistical associating fluid theory (SAFT-DFT) and grand canonical Monte Carlo (GCMC) simulations are employed to model the adsorption of CH4–CO2 mixtures on carbon slit nanopores of various sizes. We found a nonmonotonic behavior of adsorption deformation with increasing pressure and varying mixture composition that is explained by the peculiarities of molecule packings confined in nanoscale pores. The SAFT-DFT method is shown to produce results in agreement with atomistic GCMC simulations at a fraction of the computational cost. The SAFT-DFT method can be extended to study the adsorption selectivity and deformation effects for complex mixtures, including hydrocarbons and CO2.

Predicting adsorption on nanoporous carbonaceous materials is important for developing various adsorption and membrane separations, as well as for oil and gas recovery from shale reservoirs. Here, we explore the capabilities of 3D molecular models of disordered carbon structures to reproduce the morphological and adsorption features of practical adsorbents. Using grand canonical Monte Carlo simulations, we construct a series of adsorption isotherms of simple fluids (N2, Ar, CO2, and SO2) and a series of alkanes from methane to hexane on two model 3D structures, purely microporous structure A and micro-mesoporous structure B. We show that structure A reproduces the morphological properties of commercial Norit R1 Extra activated carbon and demonstrates outstanding agreement between the simulated and experimental adsorption isotherms reported in the literature for all adsorbates considered. Good agreement is also found for simulated and measured isosteric heats. Taking into account inherent variability of structural properties of commercial carbons and experimental adsorption data from different literature sources, the correlations with experiments are truly amazing. This work provides a new insight into the specifics of structural and adsorption properties of nanoporous carbons and demonstrates the advantages of using 3D molecular models for predicting adsorption hydrocarbons and other chemicals by MC simulations.