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Burch, R.; Watling, Timothy C.

doi:10.1023/a:1018974102756

Cited by 102 publications

(56 citation statements)

References 11 publications

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“…2. The above consideration is in accord with the adsorption enthalpy of propene on Pt [37] and the results of Burch and Watling [38], which show (in agreement with the present results) that unpromoted Pt/␥-Al 2 O 3 is almost ineffective for the reduction of NO by propene. Propene and its dissociation products are strongly adsorbed reducing the number of catalytically active sites.…”

Section: Discussionsupporting

confidence: 93%

Strong promotional effects of Li, K, Rb and Cs on the Pt-catalysed reduction of NO by propene

Konsolakis

Yentekakis

2001

Applied Catalysis B: Environmental

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The catalytic activity and selectivity of Pt dispersed on ␥-Al 2 O 3 for the reduction of NO by propene is promoted extremely strongly by Li, K, Rb and Cs alkalis in a wide temperature range ca. 450-800 K. Remarkable and unprecedented effects on both activity and selectivity are found. The best promotion effects are achieved by Rb-promotion, for which rate increases as high as 420-, 280-and 25-fold are obtained for the formation rates of N 2 , CO 2 and N 2 O, respectively, in comparison with the performance of un-promoted (alkali-free) Pt/␥-Al 2 O 3 . From the other hand, the selectivity towards N 2 is improved from ∼20% over the alkali-free unpromoted Pt catalyst, to >90% over the optimally alkali-promoted catalyst. These effects are understandable in terms of the effect of alkali promoter on the relative adsorption strengths of reactant species. Alkali promotes the adsorption, and consequently the dissociation, of electronegative adsorbates (NO) and inhibits the adsorption of electropositive adsorbates (propene), on a catalyst surface predominantly covered by propene and its fragments.

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Section: Discussionsupporting

confidence: 93%

Strong promotional effects of Li, K, Rb and Cs on the Pt-catalysed reduction of NO by propene

Konsolakis

Yentekakis

2001

Applied Catalysis B: Environmental

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“…Similar phenomenon was observed on Pt/Al2O3 and Pt/SiO2 catalysts [36]. This difference is related to the nature of these hydrocarbons.…”

Section: Pt/mcm-41 Catalystsupporting

confidence: 82%

“…So adsorbed oxygen is the predominant surface species [36]. Because the C-H bond energy in the CH4 molecule (105 kcal/mol) is larger than that in C3H8 molecule (95 kcal/mol), a higher C3H8 conversion was obtained using C3H8 as the reductant than that using CH4 as the reductant in the high temperature range.…”

Section: Pt/mcm-41 Catalystmentioning

confidence: 99%

Pillared Clays as Superior Catalysts for Selective Catalytic Reduction of Nitric Oxide

Long¹,

Yang²

1998

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“…Recall that O adatoms are particularly effective in inhibiting the dissociative chemisorption of methane on Pd [34]. With alkenes however, due to their much stronger interaction with the metal surface [41], a wide range of conditions exist for which the surface is predominantly covered by hydrocarbon. Na electronically enhances and inhibits the adsorption of NO and propene, respectively, as explained in detail in Ref.…”

Section: Mode Of Action Of the Na Modifiermentioning

confidence: 99%

The effect of sodium on the Pd-catalyzed reduction of NO by methane

Yentekakis

Lambert

Konsolakis

et al. 1998

Applied Catalysis B: Environmental

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The kinetics of NO reduction by methane over Pd catalysts supported on 8 mol% yttria-stabilised zirconia (YSZ) has been studied at atmospheric pressure in the 620±770 K temperature range. Langmuir±Hinshelwood type kinetics are found with characteristic rate maxima re¯ecting competitive adsorption of NO and methane: NO adsorption is much more pronounced than that of methane within the temperature range of this investigation. Pd is an effective catalyst: 100% selectivity towards N 2 can be achieved at 100% conversion of NO over this wide temperature range. Sodium causes strong poisoning of the reaction. The response of the system to variations in NO and methane concentrations, temperature, and sodium loading indicate that this is due to the Na-induced enhancement of NO chemisorption and dissociation relative to methane adsorption, i.e. sodium enhances oxygen poisoning of the catalyst. These results stand in revealing contrast to the strong promotional effect of sodium in the reduction of NO by propene over the same catalysts. The very different response of the two hydrocarbon reductants to Na doping of the Pd catalyst receives a consistent explanation. #

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Untitled

Cited by 102 publications

References 11 publications

Strong promotional effects of Li, K, Rb and Cs on the Pt-catalysed reduction of NO by propene

Strong promotional effects of Li, K, Rb and Cs on the Pt-catalysed reduction of NO by propene

Pillared Clays as Superior Catalysts for Selective Catalytic Reduction of Nitric Oxide

The effect of sodium on the Pd-catalyzed reduction of NO by methane

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