Pretreatments of Co3O4 at moderate temperature for CO oxidation at −80 °C

Yu, Yunbo; Takei, Takashi; Ohashi, Hironori; He, Huan; Zhang, Xiuli; Haruta, Masatake

doi:10.1016/j.jcat.2009.08.003

Cited by 302 publications

(273 citation statements)

References 36 publications

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“…[16] Co 3 O 4 , as a low-cost, environmentally friendly, and chemically and thermodynamically stable metal oxide, also exhibits promising properties for CO oxidation. [18][19][20][21][22][23] In this regard, Co 3 O 4 was chosen as a catalyst in the form of CeO 2 -Co 3 O 4 heteronanocomposites (HNs). It is accepted that the CO oxidation process takes place at the interface between the CeO 2 and Co 3 O 4 components.…”

Section: Introductionmentioning

confidence: 99%

Co₃O₄@CeO₂ Core@Shell Cubes: Designed Synthesis and Optimization of Catalytic Properties

Zhen¹,

Wang²,

Liu³

et al. 2014

Chemistry A European J

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Mastery of nanomaterial structure enables the control of its properties to enhance its performance for a given application. Herein, we demonstrate a fast and facile self-assembly method for the synthesis of a series of Co3 O4 @CeO2 core@shell cubes, which are characterized by SEM, TEM, XRD, inductively coupled plasma mass spectrometry (ICP-MS), and X-ray photoelectron spectroscopy (XPS) analyses. The results indicate that the thickness of the CeO2 shell can be tuned through simple variation of the feeding molar ratio of Ce/Co. These Co3 O4 @CeO2 core@shell cubes are used for catalytic CO oxidation and show good catalytic properties. Moreover, the relationship between the catalytic performance and the CeO2 shell thickness is studied in depth to optimize the catalytic properties.

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Section: Introductionmentioning

confidence: 99%

Co₃O₄@CeO₂ Core@Shell Cubes: Designed Synthesis and Optimization of Catalytic Properties

Zhen¹,

Wang²,

Liu³

et al. 2014

Chemistry A European J

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“…[56][57][58][59][60][61][62][63] One prominent feature in these practical applications is that the performance of Co 3 O 4 is closely linked with its morphology. Crystallographically, Co 3 O 4 has a spinel structure (space group of Fd3( )m) with a unit cell length of 0.8084 nm.…”

Section: Cobalt Oxidesmentioning

confidence: 99%

Tuning the Morphology of Metal Oxides for Catalytic Applications

Shen

2013

Nanocatalysis Synthesis and Applications

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“…The weakly bound oxygen ions on sites A and B are, therefore, more reactive than the strongly bound oxygen ions on site C for CO oxidation. Based on the previous report by Haruta and co-workers, [16] they also propose that, for CO oxidation, weakly bonding oxygen ions are more active than strongly bonding oxygen ions. As the number of edge atoms increases dramatically with decreasing Co 3 O 4 nanowire size, it is likely that weakly bonding oxygen ions play a crucial role in CO oxidation for the thinner Co 3 O 4 nanowires.…”

mentioning

confidence: 94%

“…As shown in Figure 6 b, two main peaks are observed in the two nanowires at the temperature of 175 and 360 8C, which could be assigned to the weakly bound oxygen ions at sites A and B and the strongly bound oxygen ions at site C, respectively. [16] [16] In summary, we have devised a novel route for the preparation of size-tunable Co(CO 3 ) 0.5 (OH)·0.11 H 2 O nanowires. The dimension of the nanowires can be controlled easily by changing the concentration of iodine ions.…”

mentioning

confidence: 99%

Iodine‐ion‐induced Size‐tunable Co₃O₄ Nanowires and the Size‐dependent Catalytic Performance for CO Oxidation

Zhu

Guo

et al. 2013

ChemCatChem

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CO oxidation is one of the most important catalytic reactions owing primarily to its relevance in practical applications in carexhaust emission control, [1] fuel cells, [2] and air purification. [3][4] Meanwhile, scientifically, it is one of the simplest catalytic reactions and thus is widely used as a model system to understand heterogeneous catalysis. [5][6][7][8] Gold nanoparticles deposited on various metal oxides that show high activity for CO oxidation have aroused tremendous interest since Haruta et al. reported that gold nanoparticles show high activity for CO oxidation. [9][10][11] Owing to the high cost of gold-based catalysts, other alternatives would be highly desirable. [12][13][14][15][16][17] As an alternative, Co 3 O 4 has been also been considered as a catalyst for CO oxidation. [12,13,18,19] Many groups have tried to control the shape of the catalyst to obtain higher catalytic efficiency, since the activity for CO oxidation strongly depends on the exposed specific crystal planes. [12,19] Moreover, several groups have synthesized small Co 3 O 4 nanoparticles that displayed much higher catalytic activity, [13,18] Figure 1 are the as-synthesized Co(CO 3 ) 0.5 -(OH)·0.11 H 2 O nanowires with the addition of NaI. The crystal phase of the as-synthesized product is determined by X-ray diffraction (XRD), with the result shown in Figure 1 a. All the identified peaks can be assigned to pure orthorhombic Co-(CO 3 ) 0.5 (OH)·0.11 H 2 O.[20] It is clear from the panoramic view (Figure 1 b) that the Co(CO 3 ) 0.5 (OH)·0.11 H 2 O nanowires comprise an uniform dandelion-like microsphere and the nanowires are uniform with 4 mm in length. Such a 1 D nanostructure is also revealed under transmission electron microscope (TEM). Under a higher magnification, these nanowires are shown to have a needle-like structure along the axial direction, and the diameter is approximately 17 nm with a smooth surface (Figure 1 c). The exposed crystal surfaces of the nanowires are (0 1 0) and (0 0 1) planes grown along the [1 0 0] direction (Figure 1 d, 1 e). Interestingly, when the samples are synthesized in the absence of NaI, the Co(CO 3 ) 0.5 (OH)·0.11 H 2 O nanowires could still be generated with the diameters of 130 nm (Supporting Information, Figure S1 e). Moreover, their arrangement is disordered and the dandelion-like microspheres no longer form (Supporting Information, Figure S1 a).Several template-free methods have been successfully applied to synthesize self-assembled structures of materials. [21][22][23][24][25][26] However, to be able to synthesize complex nanostructures of cobalt-based materials, generally high temperature and especially long reaction times are needed. [20,24,27] It was, therefore, necessary to develop a simple and effective method that could to synthesize complex cobalt-based nanostructures on a largescale in a short time. In our strategy, the formation of self-assembled Co(CO 3 ) 0.5 (OH)·0.11 H 2 O structures is faster and strongly depends on the presence of I À ions. Shown in Scheme 1 are the diff...

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Pretreatments of Co3O4 at moderate temperature for CO oxidation at −80 °C

Cited by 302 publications

References 36 publications

Co₃O₄@CeO₂ Core@Shell Cubes: Designed Synthesis and Optimization of Catalytic Properties

Co₃O₄@CeO₂ Core@Shell Cubes: Designed Synthesis and Optimization of Catalytic Properties

Tuning the Morphology of Metal Oxides for Catalytic Applications

Iodine‐ion‐induced Size‐tunable Co₃O₄ Nanowires and the Size‐dependent Catalytic Performance for CO Oxidation

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Pretreatments of Co3O4 at moderate temperature for CO oxidation at −80 °C

Cited by 302 publications

References 36 publications

Co3O4@CeO2 Core@Shell Cubes: Designed Synthesis and Optimization of Catalytic Properties

Co3O4@CeO2 Core@Shell Cubes: Designed Synthesis and Optimization of Catalytic Properties

Tuning the Morphology of Metal Oxides for Catalytic Applications

Iodine‐ion‐induced Size‐tunable Co3O4 Nanowires and the Size‐dependent Catalytic Performance for CO Oxidation

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Co₃O₄@CeO₂ Core@Shell Cubes: Designed Synthesis and Optimization of Catalytic Properties

Co₃O₄@CeO₂ Core@Shell Cubes: Designed Synthesis and Optimization of Catalytic Properties

Iodine‐ion‐induced Size‐tunable Co₃O₄ Nanowires and the Size‐dependent Catalytic Performance for CO Oxidation