Cu²⁺-acetate exchanged X zeolites: Preparation, characterization and N₂O decomposition activity

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• 作者：Bahaa M. Abu-Zied
• 关键词：Greenhouse gases ; N₂O decomposition ; X zeolites ; Cu– ; X catalyst
• 刊名：Microporous and Mesoporous Materials
• 出版年：2011
• 出版时间：March 2011
• 年：2011
• 卷：139
• 期：1-3
• 页码：59-66
• 全文大小：946 K

文摘

In this contribution a series of Cu–X zeolite catalysts were prepared utilizing ion exchange from solution method using copper(II) acetate. The calcination was affected for 3 h at air atmosphere at 550 °C. Characterization of the obtained catalysts was carried out utilizing IR, XRD, SEM, elemental analyses, N₂-adsorption, and electrical conductivity techniques. Drastic structural as well as textural changes take place after ionic exchange. Increasing copper acetate initial concentration leads to a gradual crystallinity loss together with the formation of amorphous phase. Meanwhile, Si/Al ratio of the zeolite showed a slight decrease. The observed crystallinity loss was attributed to the decrease in the solutions pH values which, in turns, favors the dealumination. Textural analysis revealed that increasing the copper ions concentration is accompanied by elimination of micropores together with the development of mesopores. Moreover, continuous decrease in S_BET, micropore surface area and micropore volume was also observed. The activity of the various catalysts was tested towards nitrous oxide decomposition. The obtained results revealed that the N₂O decomposition activity is related to the crystallinity loss as well as the relative conductivity decrease upon the admission of N₂O over the different catalysts.