Distribution of molybdenum oxidation states in reduced Mo/Al sub 2 O sub 3 catalysts. Correlation with benzene hydrogenation activity

Journal Article · Thu Sep 05 00:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100171a058· OSTI ID:5260274

Yamada, Muneyoshi ^[1]; Yasumaru, Junichi ^[2]; Houalla, M; Hercules, D M ^[3]

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1. Tohoku Univ., Sendai (Japan)
2. Kansai Coke and Chemicals Co. Ltd., Amagasaki (Japan)
3. Univ. of Pittsburgh, PA (United States)

The distribution of Mo oxidation states in reduced Mo/Al{sub 2}/Al{sub 2}O{sub 3} catalysts (8 wt % MO) has been determined by ESCA. The results show that Mo oxidation states ranging from +6 to 0 produced on reduction in the range 500-900{degrees}C. The Mo 3d binding energy values obtained for various Mo oxidation states were the same as those reported in an earlier study of Mo/TiO{sub 2} catalysts. The full widths at half-maxima for all Mo 3d peaks were larger than those for the corresponding Mo/TiO{sub 2} system. The average Mo oxidation state estimated from ESCA for a reduced catalyst agrees with that obtained by measuring the O{sub 2} consumption on reoxidation. The benzene hydrogenation activity was measured for all reduced catalysts. Significant conversion occurs only for reduction temperatures {ge} 600C. The onset of catalytic activity coincides with Mo{sup 2+} formation. However, the comparison of the distribution of Mo oxidation states determined by ESCA with the catalytic activity indicates that Mo metal is the most active species.

• DOE Contract Number: AC02-79ER10485
• OSTI ID: 5260274
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:18; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400 -- Petroleum-- Processing
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
AROMATICS
BENZENE
BINDING ENERGY
CATALYSIS
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHARGE STATES
CHEMICAL REACTIONS
DATA
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY
EXPERIMENTAL DATA
HETEROGENEOUS CATALYSIS
HYDROCARBONS
HYDROGENATION
INFORMATION
METALS
MOLYBDENUM
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REDUCTION
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TRANSITION ELEMENTS