Iron Oxide Nanoparticle-Impregnated Alumina for Catalytic Ozonation of para-Chlorobenzoic Acid in Aqueous Solution

Abstract

A granular media synthesized using iron oxide nanoparticle-coated alumina (IONA) has been demonstrated as an effective solid catalyst in the heterogeneous catalytic ozonation of para-chlorobenzoic acid (pCBA). TEM analysis showed that iron oxide nanoparticles with an average size of 5–20 nm were well-coated onto an alumina surface. It was determined that the iron oxide nanoparticle coating increased the specific surface area by 54 times and the functional group density by 1.5 times. During catalytic ozonation at acidic pH levels, it was clearly observed that IONA increased the degradation of pCBA (98 %) through effective hydroxyl radical formation compared to bare alumina (9 %) under continuous ozonation processes. In comparing the Rct value, which represents the ratio of ozone exposure to hydroxyl radical exposure, the Rct of IONA was approximately four times higher than for bare alumina. In addition, IONA showed good stability for catalytic ozonation of pCBA in the reusability tests.