Novel Isopropoxy Group-Functionalized UiO-66 with a High Hydrogen Chloride Adsorption Capacity

In this paper, a novel isopropoxy group-functionalized UiO-66 (UiO-66-IPO) was synthesized by a general strategy and then used as an adsorbent for the removal of hydrogen chloride from aqueous solutions. The as-synthesized product was characterized by X-ray powder diffraction, scanning electron microscopy, thermal gravimetric analysis, N2 adsorption and desorption isotherms, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The adsorbent showed a much higher adsorption capacity of 429.68 mg·g–1 under the initial condition of 1.4 mol·L–1 HCl concentration at 25 °C within a relatively short time (4 h). Adsorption kinetics, isotherms, thermodynamics, regeneration, and the mechanism of hydrogen chloride adsorption on the adsorbent were studied. The results showed that the hydrogen chloride adsorption process reached equilibrium quickly in 4 h, and the adsorption kinetics on UiO-66-IPO was well-described by the pseudo-second-order model. Meanwhile, the Henry isotherm ...