Catalytic decomposition of ammonia to COx-free hydrogen over Ni/ZSM-5 catalysts: A comparative study of the preparation methods

• Published in: Applied catalysis. A, General General, 2018-07, Vol.562, p.49-57
• Main Authors: Hu, Zhong-Pan, Weng, Chen-Chen, Chen, Chong, Yuan, Zhong-Yong
• Format: Article
• Language: English
• Subjects: Ammonia decomposition; Hydrogen production; Metal-support interaction; Nanocatalysts; Ni/ZSM-5 catalysts
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2018.05.038

[Display omitted] •High-activity Ni/ZSM-5 catalysts were prepared by modified solid state ion exchange (MSSIE) method.•5%Ni/ZSM-5(MSSIE) catalyst exhibited excellent catalytic stability at 650 °C for ammonia decomposition.•Strong metal-support interaction plays a key role for the formation of stable and highly dispersed Ni nanoparticles. A series of Ni/ZSM-5 catalysts are prepared by the methods of wet impregnation (IM), deposition-precipitation (DP), solid state ion exchange (SSIE), and modified solid state ion exchange (MSSIE), and used for catalytic decomposition of ammonia to COx-free hydrogen. Their physicochemical properties are characterized by XRD, N2 sorption, TEM, NH3-TPD, H2-TPR, solid-state NMR, and XPS techniques. It is revealed that the preparation methods could obviously influence the Ni species and catalytic performance of Ni/ZSM-5 catalysts, and the catalyst prepared by MSSIE method exhibits the best catalytic activity due to the presence of strong metal-support interaction between highly dispersed Ni nanoparticles and ZSM-5 support. The stability testing results showed almost no activity loss over Ni/ZSM-5(MSSIE) catalyst at 650 °C for 60 h, indicating a very promising catalyst for ammonia decomposition.