Development of porous nickel catalysts by low-temperature Ni–Al chemical alloying and post selective Al leaching, and their application for ammonia decomposition. (31st July 2020)

• Record Type: Journal Article
• Authors: Lee, Yu-Jin; Lee, Yong-Seok; Cha, Jun Young; Jo, Young Suk; Jeong, Hyangsoo; Sohn, Hyuntae; Yoon, Chang Won; Kim, Yongmin; Kim, Kwang-Bum; Nam, Suk Woo
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 38(2020)
• Page Start: 19181
• Page End: 19191
• Publication Date: 2020-07-31
• Subjects: Ni–Al alloy Powder -- Low-temperature chemical alloying (LTCA) -- Aluminum selective leaching -- Ammonia decomposition -- Hydrogen production -- Raney nickel; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.05.025
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Micron-sized Ni–Al alloy powders (Ni– x wt.%Al, x = 40, 50, 60) were synthesized using the low-temperature chemical alloying (LTCA) at 500 °C. The three different as-prepared Ni–Al alloy powders were composed of Ni2 Al3 and/or NiAl3 phases while achieving thermodynamic equilibrium compositions (Ni–40 wt%Al, Ni2 Al3 ; Ni–50 wt%Al, the coexistence of Ni2 Al3 and NiAl3 ; Ni–60 wt%Al, NiAl3 ). The LTCA method demonstrates that it is capable of producing Al-rich Ni–Al alloy powders while maintaining a particle size similar to that of the starting Ni particles. The three Ni–Al alloy powders were used as precursor materials to fabricate porous nickel catalysts through a selective aluminum leaching process, followed by the enlargement of the surface area. Alteration of the material characteristics with respect to the leaching time was investigated using XRD, FESEM-EDS, TEM, XPS, TPR, BET, and particle size analysis. The nickel skeletal catalysts with the increased BET-surface areas (50–111 m 2 /g) displayed high reactivity toward ammonia decomposition. Graphical abstract: Image 1 Highlights: Ni–Al alloy powders were synthesized by a low-temperature chemical alloying method. Post aluminum leaching converts Ni–Al alloy precursors into porous nickel catalysts. Ammonia decomposition was successfully carried out using porous nickel catalysts.