Experimental and kinetic investigation on the conversion of CO2 and iodine adsorption performance by anion-adjustable polymers under mild conditions

Abstract

Eliminating the impact of carbon dioxide (CO₂) emissions causing by anthropogenic activities is of paramount significance. The transformation of CO₂ into high-value chemicals represents one of the most effective strategies for mitigating the effects of greenhouse gases. In this study, we reported the construction of cauliflower-shaped high-efficiency polymers through a straightforward one-step solvothermal method, resulting in facile production of anion-adjustable ionic polymers, specifically DVB-MAC-X (X = Cl, Br, I, Ac, OTs). These materials were evaluated for their potential in CO₂ conversion and iodine vapor adsorption, demonstrating excellent performance in both applications. The structural framework and morphology of the polymers were validated through an array of characterizations, including Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG), nitrogen adsorption and desorption, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and solid-state nuclear magnetic resonance (¹³C-NMR). All of the synthesized polymers demonstrated satisfactory catalytic properties. DVB-MAC-I notably achieved a high conversion rate of 94.5 % to cyclic carbonate under conditions of a catalytic loading of 40 mg, a temperature of 80 °C, and a reaction time of 12 h in the absence of a co-catalyst. Moreover, the activation energy for this reaction was determined to be 54.39 kJ·mol^–1 based on kinetic experiments. Furthermore, DVB-MAC-TS demonstrated a maximum adsorption capacity of 3.7 g·g^–1 for iodine, attributed to the synergistic interactions of physical and chemical adsorption.