title: Support-dependent active species formation for CuO catalysts: Leading to efficient pollutant degradation in alkaline conditions.
abstract: Redox metal ions play the crucial role in versatile advanced oxidation technologies, in which controlling the active species formation through catalyst design is one of the key challenges in oxidant utilization. This work describes an example of different active species formations in CuO-mediated degradation just because of supporting material differences. Although three CuO catalysts were prepared by similar procedures, it was found that CuO-MgO catalyst demonstrated high efficiency in phenol degradation with bicarbonate activated H2O2, in which the superoxide radical is crucial, while hydroxyl radical and singlet oxygen are ignorable. For the CuO-MgO-Al2O3and CuO-Al2O3catalysts, the degradation proceeds by popular hydroxyl radical based process, however, the efficiency was poor. The EPR experiments also confirmed the absence of hydroxyl radical in CuO-MgO system but its presence in CuO-MgO-Al2O3and CuO-Al2O3system. The high catalytic efficiency with ignorable hydroxyl radical in the CuO-MgO system leads us to propose that an alternative Cu(III) species dominates the degradation. The basic MgO support may facilitate the formation of the Cu(III) species, whereas the neutral MgO-Al2O3and acidic Al2O3supports are unable to stabilize the high valent Cu(III) species, leading to the common hydroxyl radical mechanism with low efficiency of H2O2in alkaline conditions.
authors.affiliation: School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, PR China; School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, PR China.
authors.forename: Lianshuang
authors.initials: L
authors.lastname: Guo
authors.affiliation: Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, PR China.
authors.forename: Dekang
authors.initials: D
authors.lastname: Huang
authors.affiliation: School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, PR China.
authors.forename: Ali
authors.initials: A
authors.lastname: Jawad
authors.affiliation: School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, PR China.
authors.forename: Zhuqi
authors.initials: Z
authors.lastname: Chen
authors.affiliation: College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
authors.forename: Jiakuan
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Liu
authors.affiliation: Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, PR China.
authors.forename: Mingkui
authors.initials: M
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, PR China. Electronic address: gyin@hust.edu.cn.
authors.forename: Guochuan
authors.initials: G
authors.lastname: Yin
keywords: Active species; Copper oxide; Degradation mechanism; Supporting materials; Wastewater treatment