Efficient Selective Catalytic Reduction of NO by Novel Carbon-doped Metal Catalysts Made from Electroplating Sludge

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• 作者：Jia Zhang ; Jingyi Zhang ; Yunfeng Xu ; Huimin Su ; Xiaoman Li ; Ji Zhi Zhou ; Guangren Qian ; Li Li ; Zhi Ping Xu
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：October 7, 2014
• 年：2014
• 卷：48
• 期：19
• 页码：11497-11503
• 全文大小：382K
• ISSN：1520-5851

文摘

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 掳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.