Hydrothermal synthesis of Ag-Mn@ZSM-5: An effective catalyst for catalytic oxidation of chlorobenzene

In the current study, catalytic oxidation technology is among the most widely used methods for removing chlorinated volatile organic compounds (CVOCs). This article details the preparation of the Ag-Mn@ZSM-5 catalyst, which was prepared via the hydrothermal approach, followed by the incorporation of nano-Ag. The focus of the study is the catalytic oxidation of chlorobenzene (CB). Experimental results indicate that the hydrothermally synthesized nano-silver modified Ag-Mn@ZSM-5 catalyst, exhibiting a T90 of 290 degrees C, demonstrates superior performance compared to the Ag-Mn/ZSM-5 catalyst prepared via the traditional impregnation method, which has a T90 of 365 degrees C. As the operating airspeed increased from 7000 h- 1 to 42000 h-1, the removal efficiency of CB consistently remained above 90%, with stability maintained over a duration of 30 h. Furthermore, the catalyst exhibited excellent water resistance during a 12 h switching water test. Based on the characterization results, after loading Ag, the ratio of Mn4+ and Mn3+ on the surface of the Ag-Mn@ZSM-5 catalyst increases, the reducibility is enhanced, and the surface adsorbed oxygen species is increased, which is conducive to improving the catalytic activity. In addition, the Ag-Mn@ZSM-5 catalyst possesses an optimal pore structure, the proportion of mesoporous is 79.06%, suitable redox capacity, abundant acidic sites, and features a compact crystal stacking structure, which results in remarkable stability, catalytic activity, and space velocity resistance of the catalyst. These advantageous properties facilitate the adsorption and deep oxidation of CB. This study presents promising prospects for industrial applications and aims to offer innovative strategies for the treatment of chlorinecontaining waste gases.