Composition of Pd-La/?-Al2O3 catalysts

Subramanian, S.; Kudla, Robert; Peters, Charles R.; Chattha, M. S.

doi:10.1007/bf00764344

Cited by 23 publications

(17 citation statements)

References 14 publications

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“…On the other hand, reducibility may indicate that these palladium oxide species are located at hydrophilic sites, where retardation of the rate of reduction has a minimal effect owing to the weak interaction of water with vicinal carbon surface groups. The second peak and the small high-temperature peaks may be related to the reduction of more strongly dispersed species, e.g., those located in the pores, or deposited in the vicinity of hydrophilic surface groups [28,29]. The high-temperature maxima have sometimes been attributed to the consumption of hydrogen in the reaction with CO 2 and the production of methane [30].…”

Section: Resultsmentioning

confidence: 96%

Reduction and oxidation of a Pd/activated carbon catalyst: evaluation of effects

Biniak

Diduszko

Gac

et al. 2010

Reac Kinet Mech Cat

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A commercial Pd/activated carbon catalyst (10%) was treated using several redox processes: reduction with gaseous hydrogen at 140°C, reduction by negative electrochemical polarization in acidic and basic environments, oxidation with aqueous hydrogen peroxide, and positive electrochemical polarization in acidic and basic environments. To establish the electrochemical reduction/oxidation conditions, the potentials of hydrogen and oxygen evolution at Pd/AC powder electrodes were determined from cyclic voltammetric (CV) measurements. The samples were examined for the presence of palladium oxide phases on dispersed metal particles using XRD, TPR, and TPD. The metal oxide phase disappeared following hydrogen and electrochemical reduction. Oxidative treatment of the commercial catalyst differentiated the palladium oxide layers on the metal particle surface. Changes in the surface chemistry of the Pd/PdO/AC system were confirmed by the electrochemical behavior of electrodes prepared from the carbon samples.

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Section: Resultsmentioning

confidence: 96%

Reduction and oxidation of a Pd/activated carbon catalyst: evaluation of effects

Biniak

Diduszko

Gac

et al. 2010

Reac Kinet Mech Cat

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“…It indicated that the presence of La 2 O 3 on PdCZL hindered the reduction of PdO and helped PdO to maintain a more cationic state. Subramanian et al [32] reported that the increase of ability of oxygen transfer on ceria-lanthana interface can hinder the reduction of PdO.…”

Section: Catalytic Activitymentioning

confidence: 99%

“…2, the reduction peak of CeO 2 -ZrO 2 shifted to lower temperature, which was attributed to the presence of Pd promoting the reduction of CeO 2 via spilling of hydrogen species over the support [1,2]. PdO can be reduced to metallic Pd at the temperature lower than 200 8C [32][33][34][35]. Barrera et al [33,34] [35].…”

Section: Catalytic Activitymentioning

confidence: 99%

Preparation of CexZr1−xO2 (x=0.75, 0.62) solid solution and its application in Pd-only three-way catalysts

Guo¹,

Lu²,

Zhang³

et al. 2007

Catalysis Today

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“…The catalytic properties of Pd have received increasing attention because of its potential for the substitution of Rh in the conventional three-way Rh/Pt catalysts [6][7][8][9]. However, the Pd-only catalyst has a poor NO reduction efficiency compared to Rh, especially in an oxygen-rich environment [10,11]. Attempts to improve the catalytic performance of Pd have been made by placing it in contact with various base metal oxides and rare earth oxides.…”

Section: Introductionmentioning

confidence: 99%

Remarkable effect of addition of In and Pb on the reduction of N2O by CO over SiO2 supported Pd catalysts

et al. 2007

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The effect of addition of In and Pb on the reduction of N 2 O by CO was studied over SiO 2 supported Pd catalysts, using a closed gas circulation system as well as in-situ infrared spectroscopy. Formation of intermetallic compounds such as Pd 0.48 In 0.52 , Pd 3 Pb and Pd 3 Pb 2 was observed which caused a drastic enhancement of the rate of N 2 formation. The infrared spectroscopic analyses revealed a weakening of the adsorption strength of CO on Pd metal by the formation of intermetallic compounds, which is likely the main reason for the enhancement of the reaction rate. From a kinetic investigation as well as in situ FT-IR observation during the N 2 O-CO reaction, a redox mechanism was proposed involving the oxidation of the surface by N 2 O followed by its reduction by CO. Over Pd/SiO 2 , the former process seems to be the rate limiting step because of the inhibition of N 2 O activation by strongly adsorbed CO. By adding In or Pb, the rate limiting step shifted to the latter process, which resulted in a large enhancement in the rate of N 2 formation.

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Composition of Pd-La/?-Al2O3 catalysts

Cited by 23 publications

References 14 publications

Reduction and oxidation of a Pd/activated carbon catalyst: evaluation of effects

Reduction and oxidation of a Pd/activated carbon catalyst: evaluation of effects

Preparation of CexZr1−xO2 (x=0.75, 0.62) solid solution and its application in Pd-only three-way catalysts

Remarkable effect of addition of In and Pb on the reduction of N2O by CO over SiO2 supported Pd catalysts

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