Catalytic ozonation of toluene using Mn-M bimetallic HZSM-5 (M: Fe, Cu, Ru, Ag) catalysts at room temperature

Jihee Kim; Jung Eun Lee; Hyung Won Lee; Jong-Ki Jeon; JiHyeon Song; Sang-Chul Jung; Yiu Fai Tsang; Young-Kwon Park

doi:10.1016/j.jhazmat.2020.122577

Catalytic ozonation of toluene using Mn-M bimetallic HZSM-5 (M: Fe, Cu, Ru, Ag) catalysts at room temperature

J Hazard Mater. 2020 Oct 5:397:122577. doi: 10.1016/j.jhazmat.2020.122577. Epub 2020 May 5.

Authors

Jihee Kim¹, Jung Eun Lee¹, Hyung Won Lee¹, Jong-Ki Jeon², JiHyeon Song³, Sang-Chul Jung⁴, Yiu Fai Tsang⁵, Young-Kwon Park⁶

Affiliations

¹ School of Environmental Engineering, University of Seoul, Seoul 02504, South Korea.
² Department of Chemical Engineering, Kongju National University, Cheonan 31080, South Korea.
³ Department of Civil and Environmental Engineering, Sejong University, Seoul 05006, South Korea.
⁴ Department of Environmental Engineering, Sunchon National University, Suncheon 57922, South Korea.
⁵ Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, New Territories, Hong Kong.
⁶ School of Environmental Engineering, University of Seoul, Seoul 02504, South Korea. Electronic address: catalica@uos.ac.kr.

PMID: 32417604
DOI: 10.1016/j.jhazmat.2020.122577

Abstract

We investigated the catalytic efficiency of Mn-based bimetallic oxides in degrading toluene and ozone at room temperature. The room temperature-active bimetallic oxide catalysts were prepared by the addition of Fe, Cu, Ru, and Ag precursors to Mn/HZSM-5. We obtained H₂-temperature-programmed reduction (H₂-TPR) profiles, X-ray diffraction patterns, and X-ray photoelectron spectra to investigate the characteristics of the prepared catalysts. The catalytic efficiency of Mn-based bimetallic oxide catalysts in degrading toluene and ozone at room temperature was mostly improved by the addition of the secondary metals. The prepared bimetallic oxide catalysts, Cu-Mn/HZSM-5, Fe-Mn/HZSM-5, Ru-Mn/HZSM-5, and Ag-Mn/HZSM-5, enhanced efficiency for toluene removal compared to Mn/HZSM-5. The H₂-TPR profiles of the Mn-based bimetallic oxide catalysts showed stronger and broader adsorption-desorption bands at lower temperatures than the profile of Mn/HZSM-5. Additionally, the ratio of the surface defective oxygen over the lattice oxygen on the bimetallic oxide catalysts was higher than that of Mn-only catalysts; the ratio of Mn³⁺ over Mn⁴⁺ was higher for all bimetallic oxide catalysts, as well. Among the bimetallic oxide catalysts, Ru-Mn/HZSM-5 showed the highest efficiency for the removal of toluene to CO_x due to the synergetic effect of the oxidation state and reducible potential at room temperature.

Keywords: Catalytic ozonation; HZSM-5; Mn bimetallic oxide catalysts; Ozone; Toluene.