A Synergistic Design Strategy for Gas Storage of Aerogels via Molecular Dynamics Insights into Pore and Surface...

The efficient adsorption and storage of gases within nanoporous materials are critical for technologies such as adsorbed natural gas systems and energy storage. A paramount goal is to maximize the adsorbent's gas uptake capacity. However, the fundamental relationship between pore structure and adsorption performance in disordered aerogels remains unclear, hindering rational material design-specifically, where within the complex pore network adsorption predominantly occurs and how the pore size distribution (PSD) should be engineered to enhance capacity. To address this, we conduct molecular dynamics simulations investigating nitrogen adsorption in silica aerogels with tunable PSDs (achieved via tensile deformation) and varied gas-solid interaction strengths (ε). Our results reveal a kinetic-capacity trade-off: microporous-dominated structures saturate rapidly but have limited total uptake, whereas structures with developed mesoporosity (2-10 nm) achieve higher equilibrium capacity via capillary condensation, despite slower kinetics. The interaction strength ε is identified as a key factor governing both capacity and selectivity. Synthesizing these insights, we establish dual design guidelines: to maximize storage capacity, a hierarchical network combining micropores and interconnected mesopores is essential; for optimal reversible performance in cyclic applications like adsorbed natural gas, prioritizing open mesopores with moderately tuned surface chemistry is key. This work clarifies key aspects of the structure-performance relationships and provides evidence-based design guidelines for designing advanced aerogel adsorbents tailored for efficient, low-pressure gas storage.