Crystallographic study of cerium aluminate (CeAlO<sub>3</sub>)

Kim, Y.S.

doi:10.1107/s0567740868002219

Cited by 35 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This strongly supports the idea of the occupation of an Al(III) cationic state in the first layers by supported Ce(III) cations. Despite the difference in ionic radii (1.03 Å for Ce(III) and 0.50 Å for Al(III)), CeAlO 3 can be formed. − On the other hand, Ce(III) cations would occupy vacant octahedral coordinated sites on the surface of alumina and block the transition of Al(III) cations from tetrahedral to octahedral sites during high-temperature treatment, which caused the loss of the surface area of alumina, as previously shown in ref .…”

Section: Discussionmentioning

confidence: 61%

Surface Behavior of Alumina-Supported Pt Catalysts Modified with Cerium as Revealed by X-ray Diffraction, X-ray Photoelectron Spectroscopy, and Fourier Transform Infrared Spectroscopy of CO Adsorption

et al. 2004

View full text Add to dashboard Cite

The effects of the carrier and pretreatment temperature on the oxidation state of Ce and Pt were evaluated in Pt/Al 2 O 3 , Pt/CeO 2 , and Pt/CeO 2 -Al 2 O 3 catalyst samples with various CeO 2 loadings by applying the following spectroscopic techniques to the samples: X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy of CO adsorption. XRD showed that ceria agglomerates at high CeO 2 loadings (>3 wt %) and at a high temperature of calcination. XPS spectra showed that Ce(III) is formed more easily in the presence of Pt caused by the electron transfer between Pt and CeO 2 . A variation in the intensity and a shift in the IR bands from CO adsorbed on reduced Pt were observed, as a function of the temperature of reduction and type of the support. A heterogeneous distribution of linearly adsorbed CO on Pt at terraces and defect sites was proposed for Pt/Al 2 O 3 reduced at the lower temperature (623 K), while at the higher temperature of reduction (773 K) a complete reduction of the Pt was observed. The higher reduction temperature and increasing the CeO 2 loading led to a more uniform distribution of Pt on Pt/CeO 2 -Al 2 O 3 , related to the presence of highly unsaturated Pt caused by the strong interaction between Pt and Ce-modified alumina. The electronic effect dominates in Pt/CeO 2 samples reduced at very high temperature (973 K).

show abstract

Section: Discussionmentioning

confidence: 61%

Surface Behavior of Alumina-Supported Pt Catalysts Modified with Cerium as Revealed by X-ray Diffraction, X-ray Photoelectron Spectroscopy, and Fourier Transform Infrared Spectroscopy of CO Adsorption

et al. 2004

View full text Add to dashboard Cite

show abstract

“…After the reaction was carried out under microwave conditions, the XRD analysis of the catalyst used showed that these new peaks of CeAlO 3 were pronounced, while the CeO 2 peaks became even weaker. As the reaction of CeO 2 with Al 2 O 3 to form CeAlO 3 needs a fairly high temperature (about 1000 C) [19], the acceleration in reaction rate indicated that the catalyst temperature under microwave conditions was higher than that with conventional heating even though the measured temperature was in the same range.…”

Section: Characterization Of Catalystmentioning

confidence: 98%

Untitled

et al. 2003

View full text Add to dashboard Cite

Microwave heating was applied to the catalytic reforming reaction of methane with carbon dioxide over platinum catalysts. It was found that CO 2 and CH 4 conversions and the product selectivity ðH 2 =COÞ were generally higher under microwave conditions than that obtained with conventional heating at the same measured temperature. The effect of microwave heating was attributed to the formation of hot spots with higher temperature than that measured in the bulk catalyst bed.

show abstract

“…Cerium monoaluminate (CeAlO 3 ), a perovskite rare-earth aluminate, was first synthesized by Zachariasen 1) and studied by several researchers. [2][3][4][5][6][7] CeAlO 3 is difficult to synthesize due to the stable Ce valence of 4þ in nature. It must be sintered at temperatures higher than 1500 C in inert, reducing or vacuum ambient.…”

Section: Introductionmentioning

confidence: 99%

“…It must be sintered at temperatures higher than 1500 C in inert, reducing or vacuum ambient. [2][3][4][5][6] This is possibly why CeAlO 3 has rarely been studied despite its large dielectric constant (209 at room temperature) in powder pressed pellet form. 2) Early works studies on CeAlO 3 were mainly on its structural affirmation since there were several discrepancies among different researchers.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Electric Property of CeAlO₃ Ceramics

Wang

Yamada

Nishikubo

et al. 2005

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

Cerium monoaluminate (CeAlO3) ceramics were synthesized at 1350–1500°C in a reducing atmosphere with H3BO3 as flux and characterized of their structural and electric properties. Pellets of such ceramics, sintered at 1400°C or above, showed a perovskite-like tetragonal structure with a density higher than 92% of its theoretical. These ceramic pellets were found to have a large dielectric constant higher than 600 and a small loss tangent lower than 0.04 in the frequency range of 10 kHz to 10 MHz. This sample also showed an electric conductivity of 4.71×10-9 S/cm and an optical bandgap width of 3.29 eV at room temperature.

show abstract

Crystallographic study of cerium aluminate (CeAlO₃)

Cited by 35 publications

References 3 publications

Surface Behavior of Alumina-Supported Pt Catalysts Modified with Cerium as Revealed by X-ray Diffraction, X-ray Photoelectron Spectroscopy, and Fourier Transform Infrared Spectroscopy of CO Adsorption

Surface Behavior of Alumina-Supported Pt Catalysts Modified with Cerium as Revealed by X-ray Diffraction, X-ray Photoelectron Spectroscopy, and Fourier Transform Infrared Spectroscopy of CO Adsorption

Untitled

Synthesis and Electric Property of CeAlO₃ Ceramics

Contact Info

Product

Resources

About

Crystallographic study of cerium aluminate (CeAlO3)

Cited by 35 publications

References 3 publications

Surface Behavior of Alumina-Supported Pt Catalysts Modified with Cerium as Revealed by X-ray Diffraction, X-ray Photoelectron Spectroscopy, and Fourier Transform Infrared Spectroscopy of CO Adsorption

Surface Behavior of Alumina-Supported Pt Catalysts Modified with Cerium as Revealed by X-ray Diffraction, X-ray Photoelectron Spectroscopy, and Fourier Transform Infrared Spectroscopy of CO Adsorption

Untitled

Synthesis and Electric Property of CeAlO3 Ceramics

Contact Info

Product

Resources

About

Crystallographic study of cerium aluminate (CeAlO₃)

Synthesis and Electric Property of CeAlO₃ Ceramics