Adsorption behavior of chloroform, carbon disulfide, and acetone on coconut shell-derived carbon: experimental investigation, simulation, and model study.

The adsorption performances of chloroform (TCM), carbon disulfide (CDS), and acetone (CP) were investigated and compared over self-prepared coconut shell-derived carbon (CDC) to study the adsorption behavior and mechanism of heteroatom (Cl, S, O)-containing volatile organic compounds (VOCs). The result indicates that the adsorption capacity of three typical VOCs obeys the sequence: TCM (361 mg/g) > CDS (194 mg/g) > CP (37 mg/g). However, desorption experiments show that adsorption intensity follows the order: CDS (165 °C) > TCM (147 °C) > CP (130 °C). The influence of surface oxygen-containing functional groups over CDC on adsorption performance was also studied by temperature programmed desorption (TPD) and in situ DRIFT spectra. It is implied that carbonyl in lactone and benzoquinonyl of CDC could affect VOC adsorption intensity by conjugation effect. Furthermore, adsorption isotherms of three VOCs were obtained through Grand Canonical Monte Carlo (GCMC) simulation and then fitted by classical isothermal models. Furthermore, the total adsorption potentials are calculated by potential theory, and the result follows the order: TCM (- 2.18 kJ/mol) > CDS (- 2.1 kJ/mol) > CP (- 1.5 kJ/mol). It is believed that the effect of magnetic susceptibility (χ) is more crucial than polarizability (∂) and the distance r between the interacting molecules for the potential difference.