Understanding sulfur poisoning of bimetallic Pd-Pt methane oxidation catalysts and their regeneration

Lott, Patrick; Eck, Mario; Doronkin, Dmitry E.; Zimina, Anna; Tischer, Steffen; Popescu, Radian; Belin, Stéphanie; Briois, Valérie; Casapu, Maria; Grunwaldt, Jan‐Dierk; Deutschmann, Olaf

doi:10.1016/j.apcatb.2020.119244

Cited by 58 publications

(25 citation statements)

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“…Several studies have been performed to investigate the deactivation mechanism and impact of SO 2 on the reactivity of Pt/Al 2 O 3 catalyst for CO, NO, ,, and hydrocarbon oxidation . Additionally, many studies have focused on the deactivation of Pd/Al 2 O 3 and Pd–Pt/Al 2 O 3 catalysts by SO 2 in the complete oxidation of methane. ,− Gracia et al have reported that in the presence of continuous cofeeding of 20 ppm of SO 2 in 1% CO–10% O 2 /He, a higher sulfur storage capacity of alumina than silica was found, which postponed the poisoning of the Pt surface. This subsequently delayed the deactivation of the Pt/Al 2 O 3 catalyst compared to that of Pt/SiO 2 .…”

Section: Introductionmentioning

confidence: 99%

“…In general, the presence of sulfur strongly inhibits the oxidation of CO but promotes C 3 H 8 oxidation, while the impact of sulfur is more complex for NO and C 3 H 6 oxidation. Although some extended studies have investigated the interaction of sulfur with both monometallic and bimetallic Pd–Pt/Al 2 O 3 , most of those studies have focused on the impact of sulfur on the oxidation activity of the individual gas, such as CO, NO, C 3 H 6 , C 3 H 8 , as aforementioned, and especially CH 4 , ,,, or a mixture of gases, such as CO and C 3 H 6 . The performance of the DOC units significantly depends on gas composition .…”

Section: Introductionmentioning

confidence: 99%

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The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al₂O₃Diesel Oxidation Catalysts

Woo

Ilmasani

et al. 2021

Ind. Eng. Chem. Res.

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Diesel oxidation catalysts (DOC) were investigated for oxidation activity, NO conversion stability, and sulfur poisoning/regeneration on Pd/Al2O3, Pt/Al2O3, and Pd–Pt/Al2O3 catalysts. The Pd/Al2O3 catalyst was more active for CO and hydrocarbon (C3H6 and C3H8) oxidation, while the Pt/Al2O3 catalyst efficiently oxidized NO. The formation of a Pd–Pt alloy in the Pd–Pt/Al2O3 catalyst maintained Pd in a more reduced phase, resulting in the superior activity of this catalyst for the oxidation of CO, C3H6, and NO in comparison with its monometallic counterparts. The Pd–Pt alloy not only provided more low-temperature activity but also retained the stability of NO oxidation. The Pd–Pt alloy also favored the spillover of SO2 to the alumina support, resulting in significantly higher adsorption capacity of the Pd–Pt/Al2O3 catalyst, extensively prolonging its lifetime. However, the stable sulfates on Pd–Pt/Al2O3 made it difficult to completely regenerate the catalyst. The bimetallic sample showed higher activity for CO, C3H8, and C3H6 after sulfur poisoning and regeneration.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al₂O₃Diesel Oxidation Catalysts

Woo

Ilmasani

et al. 2021

Ind. Eng. Chem. Res.

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“…Honkanen et al [23] also used CH 4 conditions to regenerate sulfur-poisoned Pd-based catalyst. According to Kinnunen et al [24] a sulfur-poisoned catalyst can be regenerated under low-oxygen conditions and Lott et al [25] also favor rich conditions to achieve efficient regeneration. In addition, H 2 usage has been studied to recover the catalyst activity [26,27].…”

Section: Introductionmentioning

confidence: 99%

Performance and Regeneration of Methane Oxidation Catalyst for LNG Ships

Lehtoranta

Koponen

Vesala

et al. 2021

JMSE

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Liquefied natural gas (LNG) use as marine fuel is increasing. Switching diesel to LNG in ships significantly reduces air pollutants but the methane slip from gas engines can in the worst case outweigh the CO2 decrease with an unintended effect on climate. In this study, a methane oxidation catalyst (MOC) is investigated with engine experiments in lean-burn conditions. Since the highly efficient catalyst needed to oxidize methane is very sensitive to sulfur poisoning a regeneration using stoichiometric conditions was studied to reactivate the catalyst. In addition, the effect of a special sulfur trap to protect the MOC and ensure long-term performance for methane oxidation was studied. MOC was found to decrease the methane emission up to 70–80% at the exhaust temperature of 550 degrees. This efficiency decreased within time, but the regeneration done once a day was found to recover the efficiency. Moreover, the sulfur trap studied with MOC was shown to protect the MOC against sulfur poisoning to some extent. These results give indication of the possible use of MOC in LNG ships to control methane slip emissions.

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“…Furthermore, the blue region denotes the deviation range for exhaust gas containing 6–14% O 2 . Often, 10% O 2 is used to study oxidation catalysts under lean operation. ,, The red region denotes the deviation between 1 and 100 ppm of SO 2 . Although sulfur is removed from a feedstock to a high degree during the fuel production process, it cannot be removed completely .…”

Section: Resultsmentioning

confidence: 99%

PdSO₄ Surfaces in Methane Oxidation Catalysts: DFT Studies on Stability, Reactivity, and Water Inhibition

et al. 2020

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Although it is experimentally difficult to observe, PdSO4 is considered to be the culprit for the reduced activity of SO2-poisoned methane oxidation catalysts. Density functional theory (DFT) predicts that the formation of bulk PdSO4 is unlikely, which explains the lack of X-ray diffraction (XRD) evidence for the PdSO4 phase. Instead, experimental observations support the idea of PdSO4 being formed on PdO as thin films. Our study found PdSO4(110) and PdSO4(111), corresponding to PdO(100) and PdO(101), respectively, to be the most likely surfaces to be found on a poisoned catalyst. On these sulfate surfaces, PdSO4(111) contains coordinatively unsaturated palladium, which enables catalytic activity. The first C–H dissociation of methane on PdSO4(111) was found to be rather accessible with an energy barrier varying between 0.74 and 0.87 eV, values similar to those reported for metallic Pd. However, the presence of hydroxyl groups increases the barrier height. Methane oxidation is also hindered by an exceptionally strong water adsorption of −1.45 eV on the PdSO4(111) surface, which causes site blocking. A significantly strong adsorption energy causes the combination of surface hydroxyl groups to form adsorbed water that is energetically favorable. The results provide a theoretical justification for the observation that SO2-poisoned PdSO4/Al2O3 catalysts produce proper methane conversion under dry conditions but perform poorly under wet feed.

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Understanding sulfur poisoning of bimetallic Pd-Pt methane oxidation catalysts and their regeneration

Cited by 58 publications

References 95 publications

The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al₂O₃Diesel Oxidation Catalysts

The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al₂O₃Diesel Oxidation Catalysts

Performance and Regeneration of Methane Oxidation Catalyst for LNG Ships

PdSO₄ Surfaces in Methane Oxidation Catalysts: DFT Studies on Stability, Reactivity, and Water Inhibition

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Understanding sulfur poisoning of bimetallic Pd-Pt methane oxidation catalysts and their regeneration

Cited by 58 publications

References 95 publications

The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al2O3Diesel Oxidation Catalysts

The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al2O3Diesel Oxidation Catalysts

Performance and Regeneration of Methane Oxidation Catalyst for LNG Ships

PdSO4 Surfaces in Methane Oxidation Catalysts: DFT Studies on Stability, Reactivity, and Water Inhibition

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The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al₂O₃Diesel Oxidation Catalysts

The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al₂O₃Diesel Oxidation Catalysts

PdSO₄ Surfaces in Methane Oxidation Catalysts: DFT Studies on Stability, Reactivity, and Water Inhibition