Total oxidation of propane on Pt/WOx/Al2O3 catalysts by formation of metastable Ptδ+ species interacted with WOx clusters

Wu, Xiaodong; Zhang, Li; Weng, Duan; Liu, Shuang; Si, Zhichun; Fan, Jun

doi:10.1016/j.jhazmat.2012.05.011

Cited by 112 publications

(88 citation statements)

References 39 publications

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“…The band that we observed at 2123 cm -1 has been observed in many other studies [20,[36][37][38][39][40][41][42][43][44][45] of CO adsorption on platinum, and has been assigned to CO adsorption on, or near, oxidized platinum sites. However, there are many different platinum-oxide phases (e.g.…”

Section: Theoretical Calculations Of Co Adsorption On Platinum and Plsupporting

confidence: 85%

Deactivation of Pt/Al2O3 during propane oxidation at low temperatures: Kinetic regimes and platinum oxide formation

O’Brien

Jenness

Dong

et al. 2016

Journal of Catalysis

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The kinetics of propane oxidation over Pt/Al 2 O 3 are investigated in this work as a function of O 2 /C 3 H 8 ratio in the 150-300 ˚C temperature range. At high O 2 /C 3 H 8 ratios, the platinum nanoparticles are saturated with oxygen and the reaction rate is zero-order with respect to the oxygen partial pressures in this regime. As the oxygen coverage decreases with decreasing O 2 /C 3 H 8 ratio, the reaction rate increases and the reaction order changes from zero-order to negative-order in the oxygen partial pressure. The reaction rate is controlled to a large extent by the oxygen coverage on the platinum nanoparticles. However, at lower temperatures and higher oxygen pressures there is a slow deactivation of the catalyst that cannot be explained by a slow change in the oxygen coverage. Diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) of adsorbed CO was performed to track the evolution of the nanoparticle structure over the course of the propane oxidation reaction and to determine whether the slow deactivation © 2016. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ 2 was caused by reconstruction of the platinum nanoparticles. We found that the platinum nanoparticles are significantly reconstructed during the course of the reaction, including the formation of a platinum oxide (PtO) which has a characteristic CO-DRIFTS band at 2123 cm -1 .The extent of PtO formation decreases with increasing temperature and, as a result, deactivation of the catalyst is less severe at higher temperatures. Unexpectedly, increasing the oxygen partial pressure resulted in less PtO formation. We believe that a different platinum oxide phase (e.g. PtO 2 or Pt 3 O 4 ) is formed at higher oxygen pressures, which is reduced to metallic platinum during CO exposure at 25 ˚C, and therefore is not detectable by CO-DRIFTS. These results are unique because they show how the nanoparticle structure evolves over many hours of propane oxidation, and how the temperature and oxygen pressure influence the reconstruction of the nanoparticles, which has implications for a wide range of reactions not limited to propane oxidation.

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Section: Theoretical Calculations Of Co Adsorption On Platinum and Plsupporting

confidence: 85%

Deactivation of Pt/Al2O3 during propane oxidation at low temperatures: Kinetic regimes and platinum oxide formation

O’Brien

Jenness

Dong

et al. 2016

Journal of Catalysis

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“…In comparison to the other studies [30][31][32][33] on the total propane oxidation by using either oxides catalysts or supported noble metal catalyst, none of the study, as per author knowledge, is reported under similar catalytic reaction conditions. However, based on GHSV (12,000), 50% propane catalytic conversion by Au-Mn/TOS is achieved at 310 • C as compared to 50% catalytic conversion by transition metal oxides catalyst (SAS 10 vol% water derived catalyst) at 175 • C and GHSV (6000) by Marin et al [30].…”

Section: Catalytic Activitymentioning

confidence: 73%

“…However, based on GHSV (12,000), 50% propane catalytic conversion by Au-Mn/TOS is achieved at 310 • C as compared to 50% catalytic conversion by transition metal oxides catalyst (SAS 10 vol% water derived catalyst) at 175 • C and GHSV (6000) by Marin et al [30]. Wu et al [32] concluded 50% propane catalytic conversion nearly at 240 • C by using 200 mg of supported platinum and tungsten catalyst (Pt/WO x /Al 2 O 3 )-wellestablished fact on platinum group metals (PGM), comparatively very expansive, acts faster than the Au. Also, as per author's knowledge, none of the study has yet identify or emphasised on the possible synergism between metals, either PGM or Au, with the other transition metal.…”

Section: Catalytic Activitymentioning

confidence: 99%

Strong synergism between gold and manganese in an Au–Mn/triple-oxide-support (TOS) oxidation catalyst

Ali

Daous

Khamis

et al. 2015

Applied Catalysis A: General

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“…The difference in activity between PtAl and RPtCeAl samples is closely related to active areas (Table S7). TOF around 200 °C (Figure b) is directly proportional to the amount of electron‐deficient Pt species, demonstrating the effectively promotional effects of platinum oxide phase on the activation of C− and C−H bonds . As for the RPtCeAl catalysts, the hydroxylation of activated surface oxygen species results in requiring higher temperature for activation of surface lattice oxygen, this is because hydroxyl activation occurs above 200 °C based on the in situ DRIFTS results.…”

Section: Figurementioning

confidence: 99%

Activation of Surface Lattice Oxygen in Ceria Supported Pt/Al₂O₃ Catalyst for Low‐Temperature Propane Oxidation

Wang

Feng

et al. 2019

ChemCatChem

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The synergy between active Pt species and ceria results in the presence of more coordinately unsaturated Pt2+ and Pt4+ species, which were found to be critical to drive C− and C−H bonds activation and enhance propane oxidation. Surface lattice oxygen on ceria in the vicinity of electron‐deficient Pt species provides the enhanced reactivity for low‐temperature propane oxidation. The reducibility and amount of activated surface oxygen species play a significant role in improving the reaction rates of propane oxidation in the 150∼300 °C temperature range. Ceria effectively promotes oxidative redispersion of platinum crystallites supported on alumina during propane oxidation in O2‐rich conditions, due to the unique ability to trap and stabilize ionic platinum.

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Total oxidation of propane on Pt/WOx/Al2O3 catalysts by formation of metastable Ptδ+ species interacted with WOx clusters

Cited by 112 publications

References 39 publications

Deactivation of Pt/Al2O3 during propane oxidation at low temperatures: Kinetic regimes and platinum oxide formation

Deactivation of Pt/Al2O3 during propane oxidation at low temperatures: Kinetic regimes and platinum oxide formation

Strong synergism between gold and manganese in an Au–Mn/triple-oxide-support (TOS) oxidation catalyst

Activation of Surface Lattice Oxygen in Ceria Supported Pt/Al₂O₃ Catalyst for Low‐Temperature Propane Oxidation

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Total oxidation of propane on Pt/WOx/Al2O3 catalysts by formation of metastable Ptδ+ species interacted with WOx clusters

Cited by 112 publications

References 39 publications

Deactivation of Pt/Al2O3 during propane oxidation at low temperatures: Kinetic regimes and platinum oxide formation

Deactivation of Pt/Al2O3 during propane oxidation at low temperatures: Kinetic regimes and platinum oxide formation

Strong synergism between gold and manganese in an Au–Mn/triple-oxide-support (TOS) oxidation catalyst

Activation of Surface Lattice Oxygen in Ceria Supported Pt/Al2O3 Catalyst for Low‐Temperature Propane Oxidation

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Activation of Surface Lattice Oxygen in Ceria Supported Pt/Al₂O₃ Catalyst for Low‐Temperature Propane Oxidation