Catalytic activity of CeO2–ZrO2 mixed oxide catalysts prepared via sol–gel technique: CO oxidation

Thammachart, Matina; Meeyoo, Vissanu; Risksomboon, Thirasak; Osuwan, Somchai

doi:10.1016/s0920-5861(01)00322-4

Cited by 171 publications

(94 citation statements)

References 21 publications

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“…This observation is in close agreement with previous analyses [20,23]. Concerning the Pt-based catalysts, important changes in the catalytic activity were observed as a function of reduction temperature and precursor used.…”

Section: Co Prox: Effect Of Reaction and Reduction Temperaturesupporting

confidence: 92%

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Influence of the metal precursor on the catalytic behavior of Pt/Ceria catalysts in the preferential oxidation of CO in the presence of H2 (PROX)

Jardim

Rico-Francés

Coloma

et al. 2015

Journal of Colloid and Interface Science

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The effect of the metal precursor (presence or absence of chlorine) on the preferential oxidation of CO in the presence of H2 over Pt/CeO2 catalysts has been studied. The catalysts were prepared using (Pt(NH3)4)(NO3)2 and H2PtCl6, as precursors, in order to ascertain the effect of the chlorine species on the chemical properties of the support and on the catalytic behavior of these systems in the PROX reaction. The results show that chloride species exert an important effect on the redox properties of the oxide support due to surface chlorination. Consequently, the chlorinated catalyst exhibits a poorer catalytic activity at low temperatures compared with the chlorine-free catalyst, and this is accompanied by a higher selectivity to CO2 even at high reaction temperatures. It is proposed that the CO oxidation mechanism follows different pathways on each catalyst. This is a previous version of the article published in Journal of Colloid and Interface Science. 2015, 443: 45-55. doi:10.1016/j.jcis.2014 3: Graphical Abstract (for review)• The presence or absence of Cl in the Pt precursor strongly affects the catalytic behavior.• The Pt precursor affects the PROX mechanism at low reaction temperatures.• At 333 K, the mechanism in the Cl-free catalyst seems to involve the -OH groups on the support.• At higher temperatures, the reaction occurs via the same mechanism on both catalysts.. Highlights (for review) AbstractThe effect of the metal precursor (presence or absence of chlorine) on the preferential oxidation of CO in the presence of H 2 over Pt/CeO 2 catalysts has been studied. The catalysts are prepared using (Pt(NH 3 ) 4 )(NO 3 ) 2 and H 2 PtCl 6 , as precursors, in order to ascertain the effect of the chlorine species on the chemical properties of the support and on the catalytic behavior of these systems in the PROX reaction. The results show that chloride species exert an important effect on the redox properties of the oxide support due to surface chlorination. Consequently, the chlorinated catalyst exhibits a poorer catalytic activity at low temperatures compared with the chlorine-free catalyst, and this is accompanied by a higher selectivity to CO 2 even at high reaction temperatures. It is proposed that the CO oxidation mechanism follows different pathways on each catalyst.

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Section: Co Prox: Effect Of Reaction and Reduction Temperaturesupporting

confidence: 92%

“…1. For all samples it was possible to observe the six main characteristic peaks of the cubic phase, fluorite structure, of CeO 2 , which are assigned to the (111), (200), (220), (311), (222) and (400) diffraction planes [20][21][22][23].…”

Section: Catalyst Characterizationmentioning

confidence: 99%

Influence of the metal precursor on the catalytic behavior of Pt/Ceria catalysts in the preferential oxidation of CO in the presence of H2 (PROX)

Jardim

Rico-Francés

Coloma

et al. 2015

Journal of Colloid and Interface Science

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“…Combined with XRD and BET results, the typical structure in Ce 0.1 Mg 0.9 -NiO contains the active sites for low temperature CO oxidation and the catalytic activity has no direct correlation with surface areas, which was similar to results presented by Thammachart et al (2001).…”

Section: Catalytic Activities Of Co Oxidationsupporting

confidence: 83%

Effect of Ni Doping on Ce-Mg-O Nanosize Catalysts for CO Oxidation

Grisdanurak

Phuphuak

Wittayakun

et al. 2009

J. Chem. Eng. Japan

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Material of CeMg mixed oxide nanoparticle doping with Ni metal can be applied as catalyst for CO oxidation reaction. It was successfully synthesized by macromolecule surfactant modified method and characterized by XRD, BET, and TEM-EDX techniques. Both alkaline-earth (Mg 2+ ) and transition metal (Ni 2+ ) doped into CeO 2 entered the lattice of CeO 2 to form a solid solution of CeMgO and CeMgNiO, respectively. Ni doping on CeMg mixed oxide showed much better activity of CO oxidation compared to CeMg mixed oxide itself.

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“…For fresh CZPA-P, the presence of two reduction peaks at 619 and 782°C indicates that there are at least two types of Ce 4+ located in different chemical environments. The reduction peak at 619°C could be assigned to the reduction of surface Ce 4+ , whereas the peak at 782°C could be assigned to the reduction of bulk Ce 4+ (He et al, 2003;Kim et al, 2007;Kim et al, 2009;Thammachart et al, 2001). The temperature of bulk reduction of fresh CZPA-P is lower than that of pure CeO 2 (Boaro et al, 2003) due to the increased mobility of bulk oxygen in fresh CZPA-P. After thermal aging, the reduction peaks in the TPR experiment with CZPA-S sample shifts slightly towards lower temperature.…”

Section: H 2 -Tprmentioning

confidence: 94%

Preparation and properties of nanophase (Ce, Zr, Pr)O2-doped alumina coating on cordierite ceramic honeycomb for three-way catalysts

Tian

2012

Braz. J. Chem. Eng.

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-Nanophase (Ce, Zr, Pr)O 2 -doped alumina coatings were prepared by impregnating the cordierite ceramic honeycomb in the sol or in the slurry of already calcined powder, respectively. The effects of preparation methods on the crystal phase, texture, oxygen storage capacity (OSC), reducibility, surface morphology and thermal stability of coatings were investigated by X-ray diffraction (XRD), the Brunauer Emmet Teller (BET) method, the oxygen pulsing technique, H 2 -temperature-programmed reduction (H 2 -TPR) and scanning electron microscopy (SEM). These nanophase (Ce, Zr, Pr)O 2 -doped alumina coatings were used as supports to prepare Pd-only three-way catalysts, and evaluated with respect to catalytic activities. The results indicate that the nanophase (Ce, Zr, Pr)O 2 -doped alumina coatings prepared by the two methods have high thermal stability. However, the coating derived from the sol shows better crystalline structure, texture, reducibility and oxygen storage capacity than the coating derived from the slurry. SEM observation shows that the morphology of the coating derived from the sol is uniform and smooth. The Pd-only catalyst derived from the sol exhibits high three-way catalytic activity at low temperature and thermal stability, suggesting a great potential for applications.

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Catalytic activity of CeO2–ZrO2 mixed oxide catalysts prepared via sol–gel technique: CO oxidation

Cited by 171 publications

References 21 publications

Influence of the metal precursor on the catalytic behavior of Pt/Ceria catalysts in the preferential oxidation of CO in the presence of H2 (PROX)

Influence of the metal precursor on the catalytic behavior of Pt/Ceria catalysts in the preferential oxidation of CO in the presence of H2 (PROX)

Effect of Ni Doping on Ce-Mg-O Nanosize Catalysts for CO Oxidation

Preparation and properties of nanophase (Ce, Zr, Pr)O2-doped alumina coating on cordierite ceramic honeycomb for three-way catalysts

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