HKUST-1 and its graphene oxide composites: Finding an efficient adsorbent for SO2 capture

Abstract To develop effective SO2 adsorbents, HKUST-1 and HKUST-1 @ GO were synthesized by hydrothermal and room-temperature methods, and characterized by SEM, BET, XRD, TG and FTIR. The preparation method of the adsorbent, amount of adsorbent, initial concentration of SO2, and the influence of time and temperature on the adsorption of SO2 by HKUST-1 and HKUST-1@GO were studied. The results showed that the hydrothermally synthesized HKUST-1@1.2%GO was the best adsorbent for SO2, the SO2 concentration did not affect the final adsorption efficiency, the best adsorption time was 20 min, and the best adsorbent dose was 200 mg. The kinetics and isotherms of HKUST-1@1.2%GO were studied, and the thermodynamic parameters were calculated. The static SO2 adsorption of HKUST-1@1.2%GO conformed to the pseudo-first-order model and Freundlich model, and was a spontaneous exothermic process. Lowering the temperature is beneficial to the adsorption. At 288 K, the maximum theoretical SO2 adsorption capacity of HKUST-1 @1.2% GO was 72.49 mmol g−1. After five adsorption cycles, the adsorption efficiency only decreased by 0.8%, indicating that the adsorbent has excellent repeatability and cyclic stability.