Mechanisms of reduction of MoO3 to MoO2 reconciled?

Citation
E. Lalik et al., Mechanisms of reduction of MoO3 to MoO2 reconciled?, J PHYS CH B, 105(38), 2001, pp. 9153-9156
Citations number
34
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHYSICAL CHEMISTRY B
ISSN journal
15206106 → ACNP
Volume
105
Issue
38
Year of publication
2001
Pages
9153 - 9156
Database
ISI
SICI code
1520-6106(20010927)105:38<9153:MOROMT>2.0.ZU;2-F
Abstract
The topotactic mechanism for the reduction of MoO3 to MoO2 has been well-su pported by experiments, though the detection of Mo4O11 during the process h as been a challenge to the notion of direct conversion. In this study, high quality in-situ Neutron Powder Diffraction (NPD) has been used to monitor phase composition during the reduction Of MoO3 in a flow of hydrogen at 550 degreesC. Three phases have been detected: MoO3, MoO2, and Mo4O11. Multiph ase Rietveld refinement has been used to obtain concentration profiles for all three oxides throughout the reduction process. Examination of these pro files reveals the following: (1) a higher content, initially, of MoO2 than Mo4O11; (2) a period of constant MoO2 content; (3) an induction period of M o4O11 formation; and (4) a resumption in growth of MoO2 but with different unit cell dimensions.