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Updated: Feb 7, 2026

Ammonia Synthesis at Low Pressure
Published on: August 23, 2017
Effects of Na+ on Cu/SAPO-34 for ammonia selective catalytic reduction
Can Wang1, Chen Wang2, Jun Wang1
1Key Laboratory for Green Chemical Technology of State Education Ministry, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300350, China.
Abstract:
Copper-exchanged chabazite (Cu/CHA) catalysts have been found to be affected by alkali metal and alkaline earth ions. However, the effects of Na+ ions on Cu/SAPO-34 for ammonia selective catalytic reduction (NH3-SCR) are still unclear. In order to investigate the mechanism, five samples with various Na contents were synthesized and characterized. It was observed that the introduced Na+ ion-exchanges with H+ and Cu2+ of Cu/SAPO-34. The exchange of H+ is easier than that of isolated Cu2+. The exchanged Cu2+ ions aggregate and form "CuAl2O4-like" species. The NH3-SCR activity of Cu/SAPO-34 decreases with increasing Na content, and the loss of isolated Cu2+ and acid sites is responsible for the activity loss.
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