Effective toluene oxidation under ozone over mesoporous MnO x /γ-Al 2 O 3 catalyst prepared by solvent deficient method: Effect of Mn precursors on catalytic activity

• Published in: Environmental research 2021-04, Vol.195, p.110876
• Main Authors: Reddy, Kannapu Hari Prasad, Kim, Beom-Sik, Lam, Su Shiung, Jung, Sang-Chul, Song, JiHyeon, Park, Young-Kwon
• Format: Article
• Language: English
• Subjects: Catalysis; Oxidation-Reduction; Ozone; Solvents; Toluene
• ISSN: 1096-0953

In this study, the role of manganese precursors in mesoporous (meso) MnOx/γ-Al O catalysts was examined systematically for toluene oxidation under ozone at ambient temperature (20 °C). The meso MnOx/γ-Al O catalysts developed with Mn(CH COO) MnCl , Mn(NO ) .4H O and MnSO were prepared by an innovative single step solvent-deficient method (SDM); the catalysts were labeled as MnO /Al O (A), MnO /Al O (C), MnO /Al O (N), and MnOx/Al O (S), respectively. Among all, MnO /Al O (C) showed superior performance both in toluene removal (95%) as well as ozone decomposition (88%) followed by acetate, nitrate and sulphated precursor MnO /Al O . The superior performance of MnO /Al O (C) in the oxidation of toluene to CO is associated with the ozone decomposition over highly dispersed MnO in which extremely active oxygen radicals (O , O and O ) are generated to enhance the oxidation ability of the catalysts greatly. In addition, toluene adsorption over acid support played a vital role in this reaction. Hence, the properties such as optimum Mn /Mn ratio, acidic sites, and smaller particle size (≤2 nm) examined by XPS, TPD of NH , and TEM results are playing vital role in the present study. In summary, the MnO /Al O (C) catalyst has great potential in environmental applications particularly for the elimination of volatile organic compounds with low loading of manganese developed by SDM.