title: Ru(III) catalyzed permanganate oxidation of aniline at environmentally relevant pH.
abstract: Ru(III) was employed as catalyst for aniline oxidation by permanganate at environmentally relevant pH for the first time. Ru(III) could significantly improve the oxidation rate of aniline by 5-24 times with its concentration increasing from 2.5 to 15 μmol/L. The reaction of Ru(III) catalyzed permanganate oxidation of aniline was first-order with respect to aniline, permanganate and Ru(III), respectively. Thus the oxidation kinetics can be described by a third-order rate law. Aniline degradation by Ru(III) catalyzed permanganate oxidation was markedly influenced by pH, and the second-order rate constant (ktapp) decreased from 643.20 to 2.67 (mol/L)⁻¹sec⁻¹ with increasing pH from 4.0 to 9.0, which was possibly due to the decrease of permanganate oxidation potential with increasing pH. In both the uncatalytic and catalytic permanganate oxidation, six byproducts of aniline were identified in UPLC-MS/MS analysis. Ru(III), as an electron shuttle, was oxidized by permanganate to Ru(VI) and Ru(VII), which acted the co-oxidants for decomposition of aniline. Although Ru(III) could catalyze permanganate oxidation of aniline effectively, dosing homogeneous Ru(III) into water would lead to a second pollution. Therefore, efforts would be made to investigate the catalytic performance of supported Ru(III) toward permanganate oxidation in our future study.
authors: State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China. Electronic address: zhangjing2336@163.com.
authors: Jing
authors: J
authors: Zhang
authors: CSCEC AECOM Consultants Co. Ltd., Beijing 100044, China.
authors: Ying
authors: Y
authors: Zhang
authors: Waters Co., Shanghai 200000, China.
authors: Hui
authors: H
authors: Wang
authors: State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China. Electronic address: guanxh@tongji.edu.cn.
authors: Xiaohong
authors: X
authors: Guan
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D017895:Manganese Compounds / Q000737:chemistry*; D008962:Models, Theoretical; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D017895:Manganese Compounds; D010087:Oxides; C048856:permanganic acid; D012428:Ruthenium; C023650:aniline
keywords: Aniline; Byproduct; Catalysis; Electron shuttle; Ruthenium