An XPS and reduction study of PrCoO3

A series of naometric perovskite catalysts LaCo 1-x Pd x O 3 (x = 0, 0.01, 0.03) were prepared via a solution combustion synthesis route using metal nitrates as oxidizers and urea as fuel. It is essential to add a certain amount of ammonia aqueous solution to Pd 2? ions solution in the catalyst preparation process. Homogeneous nanoparticles LaCo 1-x Pd x O 3 catalysts with the sizes in the range of 68-122 nm were obtained and characterized by using of XRD, BET, H 2 -TPR, XPS, SEM and TEM. Pd was successfully introduced into the LaCoO 3 perovskite lattices. Further information was obtained by using XPS upon the LaCo 0.97 Pd 0.03 O 3 (with NH 4 OH) sample after H 2 -TPR. The results revealed that surface Pd was reduced to the metallic state at the end of the first step in the H 2 -TPR experiment, and some surface Co could be reduced to metallic Co simultaneously. The catalytic properties were investigated for simultaneous NO x -soot removal reaction. The performance of LaCo 1-x Pd x O 3 catalysts were greatly improved by the partial substitution of Pd. The maximum NO conversion into N 2 and the ignition temperature of soot are 32.8% and 265°C, respectively.

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“…This is consistent with the findings of the literatures in this field [1,6,[27][28][29]. In the first step, Co 3?…”

Section: Temperature-programmed Reduction By Hsupporting

confidence: 93%

“…is reduced to Co O [6]. Similar results have been published for LaCoO 3 perovskite [1,6,[27][28][29].…”

Section: Temperature-programmed Reduction By Hsupporting

confidence: 77%

LaCo1−x Pd x O3 Perovskite-Type Oxides: Synthesis, Characterization and Simultaneous Removal of NO x and Diesel Soot

2009

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“…8 and Table 4. Two successive reduction steps are observed for all the LaCoO 3 , as reported by several authors [34][35][36]. The first reduction step is described in the literature as the reduction of the Co 3+ into Co 2+ and the formation of the brownmillerite structure LaCoO 2.5 :…”

Section: Temperature Programmed Reduction By H 2 (Tpr)mentioning

confidence: 79%

Effect of the synthesis conditions on the redox and catalytic properties in oxidation reactions of LaCo1−xFexO3

Royer

Bérubé

Kaliaguine

2005

Applied Catalysis A: General

223

144

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“…These features promise for a wide range of applications in the solid oxide fuel cells, magnetic recording heads, permanent magnets, and suitable catalysts or support for combustion processes, CO oxidation, methane reforming, SO 2 reduction, N 2 O to N 2 and O 2 , etc. [10][11][12][15][16][17][18][19][20][21][22]. SrCoO 3 is the well studied perovskite in the Sr homologous cobalt oxide series.…”

Section: Introductionmentioning

confidence: 99%

Syntheses and Magnetic-Properties of Zn-Diluted Sr-Based Perovskite Cobalt Oxides, Sr1−x Zn x CoO3; 0.05≤x≤0.3

Balamurugan

2012

J Supercond Nov Magn

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In order to check the solubility of Zn in the (Sr 1−x Zn x )CoO 3 perovskite structure and their research findings, several polycrystalline samples have been prepared under wide extreme synthesis conditions at 6 GPa/1300-1650°C. While 0.05 ≤ x ≤ 0.3 compositions revealed single phased cubic structure materials, x > 0.3 showed multiphased materials for (Sr 1−x Zn x )CoO 3 system. Like other substituted perovskite cobalt oxide systems (Ca, Y, Ho and Ce), the transport properties of the present materials show rather sizable changes with respect to 'x', although there are insignificant variations in lattice parameter and in Curie temperature, T c . All the present samples show soft ferromagnetism with T c in the range of 272-285 K for 0.05 ≤ x ≤ 0.3. The effective paramagnetic moment, P eff determined from the paramagnetic region decreases upon the substitution of Zn for Sr-site. These P eff (3.3-2.8 µ B /Co) values for 0.05 ≤ x ≤ 0.3 compositions seem to suggest that the Co 4+ lie in intermediate spin (IS) state for the present (Sr 1−x Zn x )CoO 3 series, although they are slightly smaller than those expected for IS-Co 4+ ; P eff = 3.87 µ B /Co. The electrical resistivity is found to increase with increase of 'x' for the investigated samples. The temperature and field dependence of both positive and negative magnetoresistance (MR) are noted for the Zn substituted samples. About 5% of -MR is observed for x = 0.05 sample around the transition temperature (280 K) under the field strength difference, H = 90 kOe. The present research findings are compared with our previous results on different perovskite cobalt oxides.

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An XPS and reduction study of PrCoO3

Cited by 34 publications

References 19 publications

LaCo1−x Pd x O3 Perovskite-Type Oxides: Synthesis, Characterization and Simultaneous Removal of NO x and Diesel Soot

LaCo1−x Pd x O3 Perovskite-Type Oxides: Synthesis, Characterization and Simultaneous Removal of NO x and Diesel Soot

Effect of the synthesis conditions on the redox and catalytic properties in oxidation reactions of LaCo1−xFexO3

Syntheses and Magnetic-Properties of Zn-Diluted Sr-Based Perovskite Cobalt Oxides, Sr1−x Zn x CoO3; 0.05≤x≤0.3

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