Wenqing Wu

The separation of aromatic compounds from cyclic aliphatics has drawn decades of attention from researchers. Adsorption-based separation, an energy-saving recovery technology, can be efficiently carried out on various adsorbents. Developing cost-effective adsorbents with good selectivity and batch preparation capability is an inevitable trend. Carbon molecular sieves (CMSs) are promising, but controlling the pore size distribution is a major limitation. In this work, a series of phenolic resin-based fibrous CMSs with a concentrated distribution of ultramicropores and conjugated sp2 carbon structures was synthesized by regulating electrospinning and heat treatment. Experimental and computational studies indicate that SCF2–1000 exhibits an adsorption amount ratio of 6.8 in static adsorption, comparable to those of reported framework materials and zeolites. In equimolar benzene/cyclohexane breakthrough experiments, it achieves a high adsorption amount ratio of 11.4 and a long separation window of 2000 min g–1. FCF-1H demonstrates a dynamic adsorption selectivity factor of 30.14 and a long separation window of 8300 min g–1 in a 1:9 toluene/methylcyclohexane separation experiment. The short-range and concentrated ultramicropores allow rapid, selective adsorption and easy regeneration without decline. This work offers a feasible pathway toward separating and purifying mixed gases containing aromatics and their hydrogenation products in industrial processes.

Volatile organic compounds (VOCs) pose substantial environmental and health hazards. Adsorption is a crucial VOCs control technology, and the advancement of adsorbents is highly dependent on precise characterization via both static and dynamic adsorption measurements. Theoretically, a specific conversion relationship should exist between these two measurement methods. However, due to discrepancies in focus and testing conditions, the differences in adsorption capacities obtained by the two methods often vary considerably and lack regularity. In this study, a quantitative framework was established to bridge the gap between static and dynamic adsorption capacities by correlating them under identical partial pressures. Results indicate that the dynamic saturation adsorption capacity (Q_ds) is ca. 0.93 times the static adsorption capacity (Q_s) at the matched partial pressure (Q_ds= 0.93 × Q_s). Additionally, the dynamic penetration capacity (Q_dp) is systematically related to Q_ds through the slope (k) of the adsorption isotherm. Furthermore, by normalizing partial pressures (P/P₀), a unified predictive equation (Q_dp= (1-0.15 × k) × Q_ds) was derived. This equation can predict the concentration-dependent evolution of penetration capacity directly from equilibrium isotherms, effectively eliminating temperature effects and ensuring universal applicability. This research establishes a universal approach for calculating dynamic adsorption performance from static isotherm data, which can guide the development of tailored adsorbents for various industrial scenarios.

Adsorption capacity prediction, which needs to be based on the precise structure-capacity relationship, is important for better adsorbent design. However, the precise adsorption contribution coefficients of pores of different sizes for volatile organic compound (VOC) adsorption remain unclear. Herein, a control variable method is employed as a generative model to realize the numerization of the precise structure-capacity relationship. For the first time, a concise equation is proposed that can predict the adsorption capacities/isotherms of unknown adsorbents through their pore structure parameters. Interestingly, practical VOC adsorption amounts aligned with predicted values obtained by simultaneously considering pore volume (which undergoes volume-filling adsorption) and surface area (which undergoes surface-covering adsorption) as input variables. Derivation of the equation is based on classical adsorption theories and mathematical expression of the precise structure-capacity relationship obtained from actual experimental results. Each parameter in the equation has a specific physical meaning. This unprecedented VOC adsorption capacity/isotherm prediction method provides in-depth insight for accurate quantification of VOC adsorption, with great potential for gas adsorption prediction and guidance in the development of adsorption materials and technologies.