The adsorption mechanism of CF4 on the surface of activated carbon made from peat and modified by Cu

Abstract

In order to find a way to deal with CF4 with good removal effect and easy to promote. In this study, peat was used as raw material, and copper-loaded activated carbon (Cu/AC) was successfully prepared through nitric acid oxidation and copper chloride impregnation. Compared with commercial activated carbon and widely used metal organic frameworks (MOFs), it shows a fast adsorption rate and larger adsorption capacity for CF4. The static experiment was used to study the influence of Cu/AC on the adsorption of CF4 in the adsorbent dosage, reaction time, temperature, and initial concentration. SEM, FTIR, XPS, XRF, and BET were used to study the changes of physical and chemical properties before and after the adsorption. It was found that the oxygen-containing group was consumed during this process. Unsaturated sites on Cu can accelerate the adsorption of CF4, and the adsorption process is reversible. For the first time, the kinetic model, adsorption isotherm, and thermodynamic model are used to analyze the adsorption mechanism of CF4 on the Cu/AC surface from different angles. The results show that the adsorption of CF4 on the Cu/AC surface is a process of exothermic entropy reduction. The static adsorption process conforms to the pseudo-first-order, the pseudo-second-order, and the Freundlish adsorption model. Through 5 adsorption and desorption processes, it is found that Cu/AC has excellent recycling and recyclability performance.