This paper investigates the mechanism of nitrogen- and oxygen-containing functional groups in the collaborative adsorption of harmful gases by activated carbon through numerical simulation. The aim is to provide theoretical guidance for the industrial production of high-performance and universally applicable activated carbon. By employing density functional theory, we explore the impact of pyridine, pyrrole, carboxyl, and carbonyl groups on the co-adsorption of C₂H₆/SO₂/NO by activated carbon through analyzing surface electrostatic potential (ESP), physical adsorption energy, and non-covalent interaction. The findings demonstrate that the presence of nitrogen- and oxygen-containing functional groups within activated carbon surfaces enhances their polarity, while simultaneously forming strong non-covalent interactions with C₂H₆ and SO₂. The N-atom of NO can form a strong C-N ionic bond with the C-atom of the benzene ring. The adsorption site of NO is influenced by the nitrogen- and oxygen-containing functional groups. On an activated carbon model containing a pyrrole functional group, NO exhibits meta-adsorption behavior, while on activated carbon with pyridine, carboxyl, and carbonyl groups, it shows ortho-adsorption characteristics. The interaction between C₂H₆ and SO₂, as well as NO, primarily involves the H-bond, whereas the interaction between SO₂ and NO is predominantly driven by dipole–dipole interactions. These intermolecular forces significantly contribute to the mutual adsorption of these molecules.

In this paper, the physical adsorption of volatile organic compounds (VOCs) such as methyl chloride (CH₃Cl), carbon disulfide (CS₂), dimethyl sulfide (C₂H₆S), and benzene (C₆H₆) by three models of activated carbon (without a functional group, with a pyridine-containing functional group, and with a pyrrole-containing functional group) was simulated. The surface electrostatic potential (ESP), physical adsorption energy, and non-covalent interaction between activated carbon and VOC molecules were analyzed based on the density functional theory (DFT). The effect mechanism of nitrogen-containing functional groups on VOC adsorption by activated carbon was determined. Our simulations showed that nitrogen-containing functional groups can change the surface ESP and polarity of activated carbon. The pyrrole functional group is conducive to CH₃Cl and CS₂ adsorption on the activated carbon plane, while the pyridine functional group is relatively small or even unfavorable for CH₃Cl and CS₂ adsorption on the activated carbon plane. The promotional effect of the pyrrole functional group on the adsorption of C₂H₆S is more significant than that of the pyridine functional group. The adsorption of C₆H₆ on activated carbon occurs through parallel-displaced π–π stacking interactions, in which functional groups have little influence on it. The adsorption energy of VOCs on the activated carbon plane is higher than that at the edge, so VOCs are more likely to be adsorbed on the activated carbon plane.

Fly ash from waste incineration and waste poplar bark from furniture manufacturing are domestic wastes. In this study, fly ash and poplar bark were used as raw materials to prepare activated carbon via carbonization, steam activation and reagent modification. The effects of the raw material mixing ratio, carbonization temperature, activator concentration and modifier concentration on the physicochemical properties of the semi-coke and activated carbon were investigated through experiments. The experiment showed that when the carbonization temperature was 300 °C, the steam concentration was 20%, the mixing ratio of the poplar bark and fly ash (B:F) was 5:1, and the modifier was 6% K₂CO₃ reagent and 9% CaCl₂. The prepared activated carbon had a better yield, specific surface area and pore structure, and had an abundant surface functional group structure. This paper points out the direction for the industrial directional production of activated carbon adsorbents with excellent physical and chemical properties, which has practical significance.

CO₂ adsorption is one of the promising CCS technologies, and activated coke is a solid adsorbent with excellent adsorption properties. In this study, activated coke was prepared by using bituminous coal and coconut shells activated with KOH or CaCl₂ in a physically activated atmosphere and modified with ammonia. The effect of the active agent impregnation ratio on the physicochemical properties of activated coke was investigated by N₂ adsorption isotherms, scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). The CO₂ adsorption performance of activated coke was tested, and the effect of nitrogen-containing functional groups on CO₂ adsorption was investigated by experiments and simulations. The results showed that the specific surface area of activated coke reached 629.81 m²/g at a KOH impregnation ratio of 0.5 and 610.66 m²/g at a CaCl₂ impregnation ratio of 1. The maximum CO₂ adsorption capacity of activated coke reached 71.70 mg/g and 90.99 mg/g for conventional power plant flue gas and oxy–fuel combustion flue gas, respectively. After ammonia modification, the CO₂ adsorption capacity of activated coke was further increased. Simulations showed that pyrrole and pyrrole functional groups changed the polarity of graphene and established weak interactions with CO₂.