Effect of ZrO{sub 2}-doping of nanosized Fe{sub 2}O{sub 3}/MgO system on its structural, surface and catalytic properties

Journal Article · Sat Sep 15 00:00:00 EDT 2012 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2012.04.026· OSTI ID:22215757

Hassan, Neveen A. ^[1]; Mohamed, Ghada M.; Fagal, Gehan A. ^[1]

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1. National Research Center, Dokki, Cairo (Egypt)

Highlights: ► Preparation and characterization nano-sized ZrO{sub 2}-doped Fe{sub 2}O{sub 3}/MgO system. ► Pure and doped solids calcined at 500 and 700 °C are mesoporous adsorbents. ► ZrO{sub 2}-doping increased the lattice constant “a” of MgO lattice to an extent proportional to the amount of ZrO{sub 2} added. ► The catalytic activity in H{sub 2}O{sub 2} decomposition was found to increase as a function of dopant concentration. -- Abstract: Fe{sub 2}O{sub 3}/MgO system was prepared by wet impregnation method followed by treatment with different amounts of Zr-dopant salt then heating at 500 and 700 °C. The dopant concentrations were 0.48, 0.95 and 1.4 mol% ZrO{sub 2}. Pure and variously doped solids were characterized using XRD, N{sub 2}-adsorption isotherms carried out at −196 °C and catalytic decomposition of H{sub 2}O{sub 2} in aqueous solution at 25–35 °C. The results revealed that the nanosized MgO phase was only detected in the diffractograms of pure and doped solids calcined at 500 °C. Heating pure and doped solids at 700 °C produced nanosized MgFe{sub 2}O{sub 4} phase together with MgO phase. Pure and ZrO{sub 2}-doped solids calcined at 500 and 700 °C are mesoporous adsorbents. The doping process brought about a measurable decrease in the S{sub BET} of Fe{sub 2}O{sub 3}/MgO system with subsequent increase in its catalytic activity. The catalytic activity of the investigated system toward H{sub 2}O{sub 2} decomposition, expressed as reaction rate constant per unit surface area was found to increase as a function of dopant concentration. The maximum increase in the reaction rate constant per unit surface area measured for the reaction carried out at 30 °C attained 125% for the heavily doped samples. This significant increase was based on the catalytic activity of pure catalyst sample measured under the same conditions.

• OSTI ID: 22215757
• Journal Information: Materials Research Bulletin, Vol. 47, Issue 9; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ADSORBENTS
ADSORPTION ISOTHERMS
AQUEOUS SOLUTIONS
DECOMPOSITION
DOPED MATERIALS
FERRITES
HYDROGEN PEROXIDE
IRON OXIDES
LATTICE PARAMETERS
MAGNESIUM OXIDES
NANOSTRUCTURES
REACTION KINETICS
SOLIDS
SURFACE AREA
SURFACES
X-RAY DIFFRACTION
ZIRCONIUM OXIDES