Effect of zeolite acidity and structure on ozone oxidation of toluene using Ru-Mn loaded zeolites at ambient temperature

Jihee Kim; Eilhann E Kwon; Jung Eun Lee; Seong-Ho Jang; Jong-Ki Jeon; JiHyeon Song; Young-Kwon Park

doi:10.1016/j.jhazmat.2020.123934

Effect of zeolite acidity and structure on ozone oxidation of toluene using Ru-Mn loaded zeolites at ambient temperature

J Hazard Mater. 2021 Feb 5:403:123934. doi: 10.1016/j.jhazmat.2020.123934. Epub 2020 Sep 12.

Authors

Jihee Kim¹, Eilhann E Kwon², Jung Eun Lee¹, Seong-Ho Jang³, Jong-Ki Jeon⁴, JiHyeon Song⁵, Young-Kwon Park⁶

Affiliations

¹ School of Environmental Engineering, University of Seoul, Seoul 02504, South Korea.
² Department of Environment and Energy, Sejong University, Seoul 05006, South Korea.
³ Department of BioEnvironmental Energy, Pusan Nat. University, Miryang 50463, South Korea.
⁴ Department of Chemical Engineering, Kongju Nat. University, Cheonan 31080, South Korea.
⁵ Department of Civil and Environmental Engineering, Sejong University, Seoul 05006, South Korea.
⁶ School of Environmental Engineering, University of Seoul, Seoul 02504, South Korea. Electronic address: catalica@uos.ac.kr.

PMID: 33264983
DOI: 10.1016/j.jhazmat.2020.123934

Abstract

Five different Ru-Mn/zeolites were used to investigate their catalytic efficiencies for removing toluene (100 ppm) with ozone (1000 ppm) at room temperature. In general, most of metal oxide catalysts for removal of organic compounds need higher temperature than the ambient temperature, but Mn-based catalysts shows activity for prevalent organic pollutants even at room temperature with ozone. For the removal of toluene at room temperature without further heating, bimetallic Ru added Mn catalysts were applied in combination with different zeolite supports. The catalytic activity of the Ru-Mn catalysts strongly depended on the zeolite, of which the characteristics such as acidity and adsorption degree of toluene are dependent on the ratio of SiO₂/Al₂O₃. Among the five Ru-Mn catalysts used, Ru-Mn/HY (SiO₂/Al₂O₃ ratio: 80) and Ru-Mn/ZSM-5 (SiO₂/Al₂O₃ ratio: 80) had higher toluene and ozone removal efficiencies. The toluene removal efficiency of Ru-Mn/zeolites was proportional to the pore volume and surface area. In terms of ozone degradation, Ru-Mn/HY(80) and Ru-Mn/HZSM-5(80) had the highest removal efficiencies. Overall, the catalytic ozone oxidation of toluene using Ru-Mn/zeolites seemed to be affected by a combination of the acidic properties of zeolites, Mn³⁺/Mn⁴⁺ ratio, and concentration ratio of oxygen vacancies to oxygen lattices on the catalyst surface.

Keywords: Acidic properties; Catalytic ozone oxidation; Ru-Mn catalyst; Toluene; Zeolite.