Activated adsorption of methane on clean and oxygen-modified Pt{111} and Pd{110}

Valden, M.; Pere, Jaakko; Hirsimäki, M.; Suhonen, Sami; Pessa, M.

doi:10.1016/s0039-6028(96)01462-8

Cited by 34 publications

(24 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Below this threshold, we propose that the reaction is self-poisoned by extensive NO chemisorption, and, more crucially, by one of its dissociation products, atomic oxygen. Recall that atomic oxygen is particularly effective in retarding the dissociative chemisorption of methane on Pd [34]. Thus, under our conditions the surface of the Pd particles is covered predominately with NO and its dissociation products.…”

Section: Kinetic Behaviourmentioning

confidence: 88%

“…Recent molecular beam/infrared spectroscopy work by Chetsers et al shows unambiguously that the primary products of methane dissociative chemisorption on the surfaces of platinum group metals are CH 3 (a)H(a) [36±38]. On Pd, in the presence of oxygen adatoms, the dissociative chemisorption probability is reduced further [34] although it is unclear whether this is simply a site-blocking effect or involves longer range electronic interaction [39].…”

Section: Generalmentioning

confidence: 99%

See 1 more Smart Citation

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

Yentekakis

Lambert

Konsolakis

et al. 1998

Applied Catalysis B: Environmental

View full text Add to dashboard Cite

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. #

show abstract

Section: Kinetic Behaviourmentioning

confidence: 88%

Section: Generalmentioning

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

View full text Add to dashboard Cite

show abstract

“…For pressure-velocity coupling, the SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm was used. The discretization scheme was least squares cell based for the gradient, standard for the pressure, and second order upwind for the momentum, energy and species concentrations (O 2 , H 2 O, CH 4 , CO, and CO 2 ). Since the velocity in the present natural convection flow is very low, the residue values for continuity and momentum were taken as 10 À6 while that for energy as 10 À10 .…”

Section: Specifics Of the Computationmentioning

confidence: 99%

“…Since Pd-based catalysts have higher reactivity for methane than other catalysts, the oxidation of methane over them has been extensively studied [2][3][4][5][6][7][8][9][10][11][12]. These studies were mostly focused on certain global aspects of the catalytic process, such as the adsorption of methane [3][4][5] and oxygen [9], water poisoning [6][7][8], and the oxidation of Pd [12].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Catalytic oxidation of methane over PdO in wire microcalorimetry

Zhang

Xin

Ren

et al. 2013

Combustion and Flame

View full text Add to dashboard Cite

a b s t r a c tA two-dimensional model of a weakly buoyant flow over a horizontal wire with surface reaction was developed, using a literature mechanism, to simulate the heat release rate of the catalytic oxidation of methane (2 vol.% in air) over a Pd wire with a porous 1-2 lm PdO surface layer, acquired by wire microcalorimetry over the temperature range of 600-770 K. The experimental and simulation results demonstrate that the catalytic oxidation is characterized by a low-temperature, reaction-controlled regime in which the internal pore surface is totally accessible to the reactions, and a high-temperature regime in which finite-rate pore diffusion also affects the overall heat release rate. Furthermore, the controlling reactions are identified to be the oxidative adsorption of methane, desorption of oxygen, and adsorption of oxygen, with the former two being facilitating and the last retarding. The reaction mechanism was modified using the response surface methodology and the experimental data in the low-temperature reaction-controlled regime, yielding satisfactory prediction of the global activation energy and identification of the role of oxygen coverage in the transition of the global activation energy.

show abstract

3.8.6 Adsorbate properties of linear hydrocarbons

Rupprechter¹,

Somorjai²

Adsorbed Layers on Surfaces. Part 5: Adsorption of Molecules on Metal, Semiconductor and Oxide Surfaces

View full text Add to dashboard Cite

Activated adsorption of methane on clean and oxygen-modified Pt{111} and Pd{110}

Cited by 34 publications

References 14 publications

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

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

Catalytic oxidation of methane over PdO in wire microcalorimetry

3.8.6 Adsorbate properties of linear hydrocarbons

Contact Info

Product

Resources

About