Catalytic Activity of Argentum-loaded MCM-41 for Ozonation of p-Chlorobenzoic Acid (p-CBA) in Aqueous Solution

摘要

Argentum-loaded MCM-41 (Ag/MCM-41) was synthesized successfully by a hydrothermal method and used as a catalyst for the ozonation of p-chlorobenzoic acid (p-CBA) in aqueous solution. Ag/MCM-41 was characterized by low angle X-ray diffraction (XRD), nitrogen adsorption-desorption and transmission electron microscopy (TEM). Characterizations suggest that the prepared samples retained a highly regulated mesopores of hexagonal structure and a high BET surface area. The influences of argentum content, initial pH, reaction temperature on the catalytic ozonation were also evaluated. Ag/MCM-41/O-3 process exhibited a high catalytic activity with TOC removal at 30 min reaching 84% (only 44% by ozone alone). The presence of tert-butanol (TBA) in the process of Ag/MCM-41/O-3 inhibited the p-CBA removal, which verified the catalytic oxidation involved hydroxyl radicals. TOC removal rate only decreased 4% after being reused for four times, which indicated that Ag/MCM-41 had a good stability. Ag/MCM-41 is an effective catalyst in ozonation process.