title: Regenerable magnetic octahedral layer catalyst for gaseous UPOPs removal.
abstract: Hexachlorobenzene (HCBz), pentachlorobenzene (PeCBz), and polychlorinated biphenyls (PCBs) are a group of unintentionally produced persistent organic pollutants (UPOPs) emitted from waste combustion and industrial processes. In this study, Fe3O4 fabricated manganese oxide octahedral layer (Fe/OL) and Cu-doped OL (Fe/Cu-OL) catalysts were synthesized and they exhibited high activity for catalytic destruction of UPOPs, but also suffered from deactivation. The deactivation of Fe/Cu-OL can be assigned to the formation of surface MnClx species. As for Fe/OL, Mn sites are protected from chlorination by tunnel K(+), and the deactivation is ascribed to the blocking of active sites by KCl crystal. Simple water washing can completely regenerate the spent catalysts due to the dissolution of surface MnClx or KCl. With the advantage of magnetism, catalysts can be easily separated from water. Although Fe/Cu-OL has higher catalytic activity than Fe/OL, it is less stable in water washing due to the collapse of Mn framework structure. Considering the protection role of K(+), the spent Fe/Cu-OL was regenerated by KNO3 solution to induce additional K(+) onto the structure. In this way, the activity can be recovered while the unwanted dissolution of Mn is avoided.
authors.affiliation: POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.affiliation: POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Zhang
authors.affiliation: POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Siwen
authors.initials: S
authors.lastname: Wang
authors.affiliation: POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Shubo
authors.initials: S
authors.lastname: Deng
authors.affiliation: POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: POPs Research Center, School of Environment, State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China. Electronic address: yg-den@mail.tsinghua.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000302:isolation & purification*; D000397:Air Pollution / Q000517:prevention & control; D003300:Copper; D058185:Magnetite Nanoparticles; D017895:Manganese Compounds / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D009930:Organic Chemicals / Q000302:isolation & purification*; D010087:Oxides / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D058185:Magnetite Nanoparticles; D017895:Manganese Compounds; D009930:Organic Chemicals; D010087:Oxides; C027424:manganese oxide; D003300:Copper
keywords: Catalytic removal; Magnetic; Octahedral layer; Persistent organic pollutants; Regenerable catalyst