title: Efficient selective catalytic reduction of NO by novel carbon-doped metal catalysts made from electroplating sludge.
abstract: Electroplating sludges, once regarded as industrial wastes, are precious resources of various transition metals. This research has thus investigated the recycling of an electroplating sludge as a novel carbon-doped metal (Fe, Ni, Mg, Cu, and Zn) catalyst, which was different from a traditional carbon-supported metal catalyst, for effective NO selective catalytic reduction (SCR). This catalyst removed >99.7% NO at a temperature as low as 300 °C. It also removed NO steadily (>99%) with a maximum specific accumulative reduced amount (MSARA) of 3.4 mmol/g. Gas species analyses showed that NO removal was accompanied by evolving N2 and CO2. Moreover, in a wide temperature window, the sludge catalyst showed a higher CO2 selectivity (>99%) than an activated carbon-supported metal catalyst. Structure characterizations revealed that carbon-doped metal was transformed to metal oxide in the sludge catalyst after the catalytic test, with most carbon (2.33 wt %) being consumed. These observations suggest that NO removal over the sludge catalyst is a typical SCR where metals/metal oxides act as the catalytic center and carbon as the reducing reagent. Therefore, our report probably provides an opportunity for high value-added utilizations of heavy-metal wastes in mitigating atmospheric pollutions.
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University , No. 333 Nanchen Rd., Shanghai 200444, P. R. China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.forename: Jingyi
authors.initials: J
authors.lastname: Zhang
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Xu
authors.forename: Huimin
authors.initials: H
authors.lastname: Su
authors.forename: Xiaoman
authors.initials: X
authors.lastname: Li
authors.forename: Ji Zhi
authors.initials: JZ
authors.lastname: Zhou
authors.forename: Guangren
authors.initials: G
authors.lastname: Qian
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Zhi Ping
authors.initials: ZP
authors.lastname: Xu
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D004595:Electroplating; D007220:Industrial Waste / Q000032:analysis*; D008670:Metals / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D007220:Industrial Waste; D008670:Metals; D012722:Sewage; D009569:Nitric Oxide; D002244:Carbon