Bulk phase behavior of lithium imide-metal nitride ammonia decomposition catalysts

Journal article

Lithium imide is a promising new catalyst for the production of hydrogen from ammonia. Its catalytic activity has been reported to be significantly enhanced through its use as a composite with various transition metal nitrides. In this work, two of these composite catalysts (with manganese nitride and iron nitride) were examined using in situ neutron and X-ray powder diffraction experiments in order to explore the bulk phases present during ammonia decomposition. Under such conditions, the iron composite was found to be a mixture of lithium imide and iron metal, while the manganese composite contained lithium imide and manganese nitride at low temperatures, and a mixture of lithium imide and two ternary lithium-manganese nitrides (LixMn2-xN and a small proportion of Li7MnN4) at higher temperatures. The results indicate that the bulk formation of a ternary nitride is not necessary for ammonia decomposition in lithium imide-transition metal catalyst systems.

Authors: Makepeace, J; Wood, T; Marks, P; Smith, R; Murray, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Physical chemistry chemical physics
• Volume: 20
• Issue: 35
• Pages: 22689-22697
• Publication date: 2018-08-23
• Acceptance date: 2018-07-31
• DOI: 10.1039/c8cp02824a
• EISSN: 1463-9084
• ISSN: 1463-9076
• Pmid: 30137070
• Language: English