Surface active sites of V sub 2 O sub 5 -MoO sub 3 catalysts

Journal Article · Wed Feb 22 23:00:00 EST 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100341a059· OSTI ID:5145475

Satsuma, Atsushi; Hattori, Atsushi; Mizutani, Koichi; Miyamoto, Akira; Hattori, Tadashi; Murakami, Yuichi ^[1]; Furuta, Akio ^[2]

---

1. Nagoya Univ. (Japan)
2. JGC Corp., Aichi (Japan)

The promoting effect of MoO{sub 3} on the surface active sites of V{sub 2}O{sub 5} catalyst was investigated by using various methods, and the catalytic activity of V{sub 2}O{sub 5}-MoO{sub 3} catalysts was discussed in the light of the surface active sites and the bulk structure. The surface concentration of the redox sites, measured by the NARP (NO-NH{sub 3} rectangular pulse) technique, was increased by the addition of MoO{sub 3} to V{sub 2}O{sub 5} both on the solid solution and on the intermediate compounds, i.e., Mo{sub 4}V{sub 6}O{sub 25} and Mo{sub 6}V{sub 9}O{sub 40}. On the solid solution, the increase in the surface redox sites is attributed to the formation of the surface V = O species on various crystal planes of vanadium oxide containing solved MoO{sub 3}, although V{sub 2}O{sub 5} crystal has the surface V = O species only on the (010) plane. The increase in the surface V = O species on solid solution may cause the high activity of V{sub 2}O{sub 5}-MoO{sub 3} catalysts on various reactions, such as benzene oxidation. On the intermediate compounds, it was proved by NARP and SIMS that the surface Mo = O species act as the redox sites for the reduction of NO with NH{sub 3} in a manner similar to that of the surface V = O species on V{sub 2}O{sub 5} catalysts, although MoO{sub 3} itself is inactive at the temperature range examined. The activation of the surface Mo = O species was attributed to the atomic mixing of the surface vanadium and molybdenum ions on the exposed crystal plane of the intermediate compounds.

• OSTI ID: 5145475
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 93:4; ISSN JPCHA; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ADSORPTION
AMMONIA
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTION YIELD
COHERENT SCATTERING
DATA
DIFFRACTION
ELECTRON SPECTROSCOPY
ELECTRON SPIN RESONANCE
ELEMENTS
EXPERIMENTAL DATA
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
INFRARED SPECTRA
ION MICROPROBE ANALYSIS
MAGNETIC RESONANCE
MASS SPECTROSCOPY
MICROANALYSIS
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
NITROGEN
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONDESTRUCTIVE ANALYSIS
NONMETALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
QUANTITY RATIO
REFRACTORY METAL COMPOUNDS
RESONANCE
SCATTERING
SORPTION
SORPTIVE PROPERTIES
SPECTRA
SPECTROSCOPY
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES
X-RAY DIFFRACTION
YIELDS