Abstract: This study systematically investigates the adsorption mechanism of ethane (a critical component of volatile organic compounds, VOCs) on heteroatom-modified activated carbon, aiming to address the dual challenges of efficient ethane recovery in petrochemical industries and greenhouse gas emission reduction. To overcome the limitations of conventional activated carbon, such as restricted specific surface area and suboptimal pore structure, an innovative surface doping strategy was developed by introducing hydroxyl, carbonyl, pyridinic nitrogen, and amino functional groups. Through combined quantum chemical calculations and grand canonical Monte Carlo (GCMC) simulations, the regulatory effects of these functional groups on binding energy, weak intermolecular interactions, and electrostatic potential distribution in the activated carbon-ethane system were elucidated at the molecular level. Key findings reveal that amino-group doping achieves the highest binding energy in planar adsorption configurations, with an ethane adsorption capacity of 153.9 mL/g, representing a 10.2% enhancement over pristine activated carbon. Conversely, carbonyl-group doping exhibits optimal performance in lateral adsorption configurations, achieving a 74.0% increase in ethane adsorption capacity. Electrostatic potential analysis demonstrates that nitrogen/oxygen heteroatom doping modulates adsorption performance by redistributing surface charge density. The microscopic mechanism of ethane adsorption by activated carbon is revealed through simulation calculations, which provides a theoretical basis and design strategy for the development of high-efficiency VOCs adsorption materials.

Key words: ethane, adsorption method, activated carbon modification, heteroatom doping, simulation calculation