Effects of cobalt loading on the properties of alumina-supported cobalt oxide

Journal Article · Thu Mar 01 04:00:00 EST 1990 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(90)90274-N· OSTI ID:6437294

Tung, Huanchien; Yeh, Chuintih ^[1]; Hong, Chengtsung ^[2]

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1. National Tsinghua Univ., Hsinchu (Taiwan)
2. Chinese Petroleum Corp., Chia-Yi (Taiwan)

Recently Arnoldy and Moulijn used a combination of TPR and XRD techniques to study the variation with precalcination temperature of the properties of a reduced 9.1% CoO/Al{sub 2}O{sub 3} catalyst. In their report, cobalt oxides in four kinds of chemical environments, i.e., Co{sub 3}O{sub 4} (reduced around 600 K), a Co{sup 3+} phase on the surface (around 740 K), a Co{sup 2+} phase on the surface (around 875 K), and a CoAl{sub 2}O{sub 4} spinel structure (around 1,160 K) were distinguished from the TPR study. The relative amount of these four phases on the catalysts depended on the temperature of calcination pretreatment. A series of alumina-supported catalysts with various cobalt loadings has been prepared in this laboratory in order to investigate the effect of the metal loading on the relative concentration of the four species described by Arnoldy and Moulijn. The temperature of calcination treatment of the catalysts prepared was fixed at 773 K. The authors intention was to confirm the possible existence of Co{sub 3}O{sub 4} crystallites after the calcination treatment. DRS, XRD, and EPR spectroscopies were coupled to a TPR technique to probe the reduction of these species by the hydrogen.

• OSTI ID: 6437294
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 122:1; ISSN 0021-9517; ISSN JCTLA
• 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
CALCINATION
CATALYST SUPPORTS
CATALYSTS
CHALCOGENIDES
CHARGE STATES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COBALT COMPOUNDS
COBALT OXIDES
COHERENT SCATTERING
CONTROL
CRYSTAL STRUCTURE
DECOMPOSITION
DETECTION
DIFFRACTION
ELECTRON SPIN RESONANCE
ELEMENTS
HYDROGEN
LOADING RATE
MAGNETIC RESONANCE
NONMETALS
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PYROLYSIS
QUANTITY RATIO
REDUCTION
REFLECTIVITY
RESONANCE
SCATTERING
SPECTROSCOPY
SURFACE PROPERTIES
SYNTHESIS
TEMPERATURE CONTROL
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION