Selective CO oxidation over CeXZr1−XO2-supported Pt catalysts

Ayastuy, J.L.; González-Marcos, M.P.; Gil-Rodríguez, A.; González‐Velasco, Juan R.; Gutiérrez-Ortiz, M.A.

doi:10.1016/j.cattod.2006.05.074

Cited by 71 publications

(45 citation statements)

References 50 publications

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“…No diffraction peaks for platinum could be identified for both catalysts, consistent with the low platinum content or, more probably, a high Pt dispersion [8,20,24,25]. The crystal size for the ceria support, estimated by Scherrer's equation, was 17 nm.…”

Section: Catalyst Characterizationmentioning

confidence: 93%

“…Details regarding the possible mechanisms are reported later. Both catalysts exhibited a decrease in CO conversion and selectivity to CO 2 (not shown) at temperatures above 400 K. At these high temperatures, the oxidation of H 2 to H 2 O was more favored than the oxidation of CO to CO 2 [11,24,25,47]. However, the effect of CO 2 present in the reaction feed cannot be ruled out as being responsible for the loss in catalytic activity.…”

Section: Co Prox: Effect Of Reaction and Reduction Temperaturementioning

confidence: 99%

“…The reducibility of the different catalysts was studied by temperature- exhibites reduction peaks at 760 and 1050 K, which can be attributed to surface and bulk reduction processes, respectively [25,28,29]. Pt addition to the CeO 2 support produced important changes in the TPR profiles.…”

Section: Catalyst Characterizationmentioning

confidence: 99%

“…It is well known that cerium oxide reduction involves several processes: (i) the removal of surface carbonates [29], (ii) a change in the cerium oxidation state (Ce(IV) to Ce(III)) and (iii) -OH group formation by spillover of atomic hydrogen from Pt [28,29]. Furthermore, the surface reduction of ceria was shifted to lower temperatures in the presence of Pt [25]. This phenomenon can 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 8 be explained by the ability of the noble metal to dissociate hydrogen, thus promoting ceria reduction through spillover of hydrogen from the metal to the support [30].…”

Section: Catalyst Characterizationmentioning

confidence: 99%

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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: Catalyst Characterizationmentioning

confidence: 93%

Section: Co Prox: Effect Of Reaction and Reduction Temperaturementioning

confidence: 99%

Section: Catalyst Characterizationmentioning

confidence: 99%

Section: Catalyst Characterizationmentioning

confidence: 99%

See 2 more Smart Citations

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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“…A strong peak at 2085 cm -1 was observed. This peak corresponds to CO adsorbed on Pt with neighboring oxidized Pt [32]. Unlike platinum over ceriapromoted alumina catalyst, no peak of CO 2 gas phase was observed.…”

Section: Activity Tests For Co Oxidation Withmentioning

confidence: 99%

Removal of Carbon Monoxide from Hydrogen-rich Fuels over CeO2-promoted Pt/Al2O3

Wongkaew¹,

Limsuwan²

2013

ACES

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A comparative study of catalytic CO oxidation and selective CO oxidation over Pt/Al 2 O 3 and CeO 2 -promoted Pt/Al 2 O 3 catalysts has been investigated for the removal of a trace amount of CO from the reformed gas. The catalysts were prepared by sol gel and incipient wetness impregnation. CO oxidation and selective CO oxidation were carried out with a 5%Pt/Al 2 O 3 and a 5%Pt/15%CeO 2 /Al 2 O 3 . The presence of 15%CeO 2 in the 5%Pt/Al 2 O 3 dramatically improves the activities to CO oxidation and selective CO oxidation at low temperature (<180℃). FTIR results indicate that CO could react with lattice oxygen from ceria and release CO 2 as a product. Low space velocity would obtain high CO conversion at low temperatures while high space velocity would obtain high CO conversion at high temperatures. The results also show that a 5%Pt/15%CeO 2 /Al 2 O 3 can completely oxidize 1% CO at 180℃ with selectivity of 52% and space velocity of 70,000 cm 3 ·g -1 ·h -1 . Under the realistic gas feed with 1%O 2 , this catalyst is very stable and retains its activity and selectivity at 180℃ during 72 h.

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AuPt Alloy Nanoparticles for CO‐Tolerant Hydrogen Activation: Architectural Effects in Au‐Pt Bimetallic Nanocatalysts

Zhou

Jackson

Eichhorn

2007

Adv Funct Materials

173

127

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Colloidal suspensions of AuPt alloy nanoparticles (NPs) were prepared by using a rapid butyllithium reduction of Au3+ and Pt4+ precursors in oleylamine. The resulting 2.5 nm (av) particles were characterized by TEM with EDX, XRD, XPS and UV‐vis spectroscopy. With less butyllithium, nanowires are formed from fused NPs and grow to 100 nm in length. The activities of three different AuPt NP architectures (alloy, contact aggregate and monometallic NPs) were evaluated for catalytic hydrogen oxidation in CO‐contaminated fuel streams (1.0 % Pt loadings in Al2O3 supports). The alloy catalyst showed superior H2 and CO oxidation activity, was unaffected by iron promoters and appears to operate by a different mechanism. The heteroaggregate showed a marked improvement in activity with iron promoters and is more selective for CO oxidation.

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Selective CO oxidation over CeXZr1−XO2-supported Pt catalysts

Cited by 71 publications

References 50 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)

Removal of Carbon Monoxide from Hydrogen-rich Fuels over CeO<sub>2</sub>-promoted Pt/Al<sub>2</sub>O<sub>3</sub>

AuPt Alloy Nanoparticles for CO‐Tolerant Hydrogen Activation: Architectural Effects in Au‐Pt Bimetallic Nanocatalysts

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Selective CO oxidation over CeXZr1−XO2-supported Pt catalysts

Cited by 71 publications

References 50 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)

Removal of Carbon Monoxide from Hydrogen-rich Fuels over CeO&lt;sub&gt;2&lt;/sub&gt;-promoted Pt/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;

AuPt Alloy Nanoparticles for CO‐Tolerant Hydrogen Activation: Architectural Effects in Au‐Pt Bimetallic Nanocatalysts

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Removal of Carbon Monoxide from Hydrogen-rich Fuels over CeO<sub>2</sub>-promoted Pt/Al<sub>2</sub>O<sub>3</sub>