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

Research output: Contribution to journalArticle

Authors

  • Thomas J. Wood
  • Phillip L. Marks
  • Ronald I. Smith
  • Claire A. Murray
  • William I. F. David

Colleges, School and Institutes

Abstract

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.

Details

Original languageEnglish
Pages (from-to)22689-22697
Number of pages9
JournalPhysical Chemistry Chemical Physics
Volume20
Issue number35
Early online date23 Aug 2018
Publication statusPublished - 21 Sep 2018