Revealing the mechanism of adsorption and separation of acetone/methanol by porous carbon via experimental and theoretical calculations

Currently, the focus of research on carbon-based materials primarily revolves around studying the adsorption properties of methanol and acetone. However, there is limited research on the adsorption and separation of methanol and acetone azeotropes, and the mechanism is still unclear. Here, the impact of oxygen groups and pore size on the adsorption and separation of acetone and methanol in porous carbon materials was investigated using molecular simulations. The results demonstrated that the adsorption capacity of acetone and methanol is influenced by the micropore structure and oxygen content at relatively low pressures, while at relatively high pressures, the adsorption capacity primarily depends on pore structure. Notably, the micropore structure emerged as a key determinant of acetone/methanol selectivity, while the doping of oxygen groups in porous carbon has a negative impact on selectivity. To validate our theoretical findings, three types of porous carbons with varying oxygen contents and gradient pore size distributions were synthesized. The acetone and methanol adsorption isotherms were measured, and the acetone/methanol selectivity was calculated. Comparative analysis of the impact of pore size and oxygen content on the adsorption and separation performance of acetone and methanol yielded consistent results between experimental and theoretical calculations. These findings elucidate the effects of oxygen content and pore size on the adsorption performance of acetone and methanol adsorption and separation performance from both experimental and theoretical perspectives, providing a basis for further design and development of adsorbents of high-performance volatile organic compounds (VOCs) adsorbents.