Surface chemical structures of V/sub 2/O/sub 5/-P/sub 2/O/sub 5/ catalysts

Journal Article · Thu Apr 21 00:00:00 EDT 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100319a036· OSTI ID:7148599

Satsuma, A; Hattori, A; Furuta, A; Miyamoto, A; Hattori, T; Murakami, Y

Surface chemical structures of V/sub 2/O/sub 5/-P/sub 2/O/sub 5/ catalysts were investigated by using X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), temperature-programmed desorption (TPD) of NH/sub 3/, infrared spectra of adsorbed NH/sub 3/ and pyridine, and the NARP (nitric oxide-ammonia rectangular pulse) technique. The concentration of the surface V==O species remarkably increased with P/sub 2/O/sub 5/ content below P/V = 1.0, but it decreased on further addition of P/sub 2/O/sub 5/. The increase in the surface V=O species was attributed to the lower oxidation state of vanadium ions in the bulk of the V/sub 2/O/sub 5/-P/sub 2/O/sub 5/ catalysts. The addition of P/sub 2/O/sub 5/ increased the surface concentration and the strength of acid sites, which consist mostly of Broensted acid sites and of a slight amount of Lewis acid sites. It was concluded that, at high P/V ratio, all of the surface V and P ions act as the active functional groups; all P ions form P-OH species having a function of Broensted acid, and all V ions form the surface V=O species having a redox function.

• Research Organization: Nagoya Univ. (Japan)
• OSTI ID: 7148599
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:8; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AMMONIA
AZINES
CATALYSIS
CATALYSTS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL PLANTS
DATA
DESORPTION
ELECTRON SPECTROSCOPY
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
INDUSTRIAL PLANTS
INFORMATION
INFRARED SPECTRA
ION MICROPROBE ANALYSIS
MASS SPECTROSCOPY
MICROANALYSIS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONDESTRUCTIVE ANALYSIS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PHOSPHORUS OXIDES
PHOTOELECTRON SPECTROSCOPY
PYRIDINE
PYRIDINES
SORPTION
SPECTRA
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES