Surface characterization of chromium oxide-zirconia catalyst

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Langmuir; (United States)

DOI:https://doi.org/10.1021/la00025a029· OSTI ID:6512928

Sohn, J R; Ryu, S G ^[1]

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1. Kyungpook National Univ., Taegu (Korea, Democratic People's Republic of)

Chromium oxide-zirconia catalysts were prepared by dry impregnation of powdered Zr(OH)[sub 4] with an aqueous solution of (NH[sub 4])[sub 2]CrO[sub 4]. The surface characterization of prepared catalysts was performed by using Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), and by the measurement of surface area. The addition of chromium oxide to zirconia shifted the phase transitions of ZrO[sub 2] from amorphous to tetragonal and from tetragonal to monoclinic to higher temperatures due to the interaction between chromium oxide and zirconia. Since the ZrO[sub 2] dispersed chromium oxide, [alpha]-Cr[sub 2]O[sub 3] was observed only at the calcination temperature above 1173K. In treatments by oxygen, hydrogen, carbon monoxide, and n-hexane the reduction-oxidation between Cr(VI) and Cr(III) is reversible, as observed by XPS and IR. Upon the addition of only a small amount of chromium oxide (1 wt % Cr) to ZrO[sub 2] both the acidity and acid strength of the catalyst increased remarkably, showing the presence of Broensted and Lewis acid sites on the surface of CrO[sub x]/ZrO[sub 2]. Chromium oxide catalysts are important in reactions of environmentally significant compounds such as NO and CO. 36 refs., 10 figs., 2 tabs.

• OSTI ID: 6512928
• Journal Information: Langmuir; (United States), Journal Name: Langmuir; (United States) Vol. 9:1; ISSN LANGD5; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
COHERENT SCATTERING
DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
HEXANE
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
HYDROXIDES
IMPREGNATION
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
SCATTERING
SPECTROSCOPY
SURFACE AREA
SURFACE PROPERTIES
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
ZIRCONIUM COMPOUNDS
ZIRCONIUM HYDROXIDES
ZIRCONIUM OXIDES