The preparation of molybdenum carbonitrides by single source routes and a study of their lattice reactivity

Al shalwi, Matar (2012) The preparation of molybdenum carbonitrides by single source routes and a study of their lattice reactivity. MSc(R) thesis, University of Glasgow.

Abstract

Thermal decomposition of hexamethylenetetramine molybdate and ethylenediammonium
molybdate were studied using a temperature programmed reaction procedure under
different reaction atmospheres. The obtained materials were characterised by X-ray
diffraction (XRD), surface area measurement (BET), scanning electron microscopy
(SEM), elemental analysis (CHN), thermogravimetric analysis (TGA) and X-ray
photoelectron spectroscopy (XPS). The results indicated that the decomposition of both
precursors under H2/N2 in a ratio of 3:1 or 1:3 leads to production of molybdenum
carbide, and also a mixture of molybdenum metal and molybdenum carbide is obtained
from the thermal decomposition of both precursors under 1:3 Ar/H2. In contrast, the
decomposition of hexamethylenetetramine molybdate under N2 or Ar leads to production
of Ɣ-Mo2N, whereas impure phases were obtained from the decomposition of
ethylenediammonium molybdate where molybdenum carbide, molybdenum metal and
molybdenum oxide were obtained under an Ar atmosphere while gamma molybdenum
nitride, molybdenum carbide and molybdenum oxide were obtained under a N2
atmosphere. In order to characterise the reactivity of the lattice carbon and nitrogen
species within the obtained materials various techniques have been applied. The results
have indicated that nitrogen is much more reactive than carbon and the nature of its
reactivity is influenced by composition. The difference in reactivity observed indicates
that molybdenum carbonitrides are not suitable candidates as reagents for which the
simultaneous loss of nitrogen and carbon from the lattice would be desirable.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: molybdenum oxycarbonitride
• Subjects: Q Science > QD Chemistry; Q Science > Q Science (General)
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Supervisor's Name: Hargreaves, Dr. Justin
• Date of Award: 2012
• Depositing User: Mr matar alshalwi
• Unique ID: glathesis:2012-3346
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 16 May 2012
• Last Modified: 10 Dec 2012 14:06
• URI: https://theses.gla.ac.uk/id/eprint/3346