Mechanism for Solid-State Ion Exchange of Cu+ into Zeolites

详细信息    查看全文

• 作者：Lin ChenJonas Jansson ; Magnus Skoglundh ; Henrik Grönbeck
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：December 29, 2016
• 年：2016
• 卷：120
• 期：51
• 页码：29182-29189
• 全文大小：608K
• ISSN：1932-7455

文摘

Density functional theory calculations are used to investigate solid-state ion exchange of copper into zeolites. In particular, the energetic conditions for functionalization of chabazite (CHA) with copper ions from Cu₂O(111) via formation of Cu(NH₃)₂⁺ are explored. It is found that the diamine complexes form easily on Cu₂O(111) and diffuse with low barriers over the surface and in the CHA framework. The charge neutrality of the systems is maintained via counterdiffusion of H⁺ in the form of NH₄⁺ from the zeolite to the Cu₂O surface where water can be formed. The efficient solvation of Cu⁺ and H⁺ by ammonia renders the ion-exchange process exothermic. The present results highlight the dynamic character of the Cu ion sites and provide means to understand zeolite functionalization.