Assessing the effect of O2 dithering on CH4 oxidation on Pd/Al2O3

Roger, Maneka; Kröcher, Oliver; Ferri, Davide

doi:10.1016/j.cej.2022.138865

Cited by 12 publications

(5 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, catalytic deactivation is a common shortcoming for the industrial catalysts. , Under the practical reaction conditions, the formation of coke, coverage of the active site by the reactants or intermediates, and sintering of particles at high temperature might lead to a decrease of the catalytic performance. For example, the strong chemisorption of CO on the noble metal site will block the dissociative adsorption of O 2 and then poison the catalysts for low-temperature oxidation reactions. , In the case of the catalytic combustion of chlorinated VOCs (CVOCs), the deactivation phenomenon of the used catalysts is attributed to the accumulation of Cl species and the coverage of active sites. , Due to the stable structure of CH 4 , it is a great challenge for the catalyst to retain the original morphology and structure after catalytic combustion at high temperature . Usually, not only could the air pollutants influence the catalytic stability but also the presence of other impurities could affect the catalytic stability.…”

Section: Introductionmentioning

confidence: 99%

“…16,17 Due to the stable structure of CH 4 , it is a great challenge for the catalyst to retain the original morphology and structure after catalytic combustion at high temperature. 18 Usually, not only could the air pollutants influence the catalytic stability but also the presence of other impurities could affect the catalytic stability. The traditional catalysts might be prematurely aged and inactivated in the complex industrial gas atmosphere (including SO 2 , CO 2 , H 2 O, and so on).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Review and Perspectives of Enhancement in the Catalytic Stability for the Complete Combustion of CO, CH₄, and Volatile Organic Compounds

et al. 2023

View full text Add to dashboard Cite

As typical air pollutants, CO, CH4, and volatile organic compounds (VOCs) have received great attention due to their negative impact on the environment and human health. Heterogeneous catalysts are widely used in the catalytic removal of exhaust emission from industrial and automobile sources but still suffer from deactivation because of various factors. The development of a catalyst with excellent catalytic stability is highly desired. We herein summarized the recent progress for enhancing the catalytic stability of catalysts and tried to obtain an in-depth understanding of the long-term durability, resistance to sinter, and tolerance for multi-impurities. Finally, the current challenges and future perspectives for developing stable and highly efficient catalysts in the fields of synergistic catalytic removal of pollutants or resource utilization of VOCs via the selective catalytic oxidation are proposed.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Review and Perspectives of Enhancement in the Catalytic Stability for the Complete Combustion of CO, CH₄, and Volatile Organic Compounds

et al. 2023

View full text Add to dashboard Cite

show abstract

“…29–0063). [ 29 ] The diffraction peaks for Pd species, which generally appear at ≈40.1°, 46.7°, 68.1°, 82.1°, and 86.6° (JCPD No. 05–0681), are missing.…”

Section: Resultsmentioning

confidence: 99%

A Novel Pd Precursor Loaded γ‐Al₂O₃ with Excellent Adsorbent Performance for Ultra‐Deep Adsorptive Desulfurization of Benzene

Xie

Dai

et al. 2023

Adv Funct Materials

View full text Add to dashboard Cite

Fabricating highly water‐soluble and chlorine‐free precursors from Pd complexes remains challenging. Here, a novel Pd precursor (ammonium dinitrooxalato palladium(II) ((NH4)2[Pd(NO2)2(C2O4)]·2H2O)) is synthesized to address this challenge. Additionally, a Pd/Al2O3 adsorbent is prepared using γ‐Al2O3 as a base material to host Pd. The ligand action of the Pd complex forms single Pd atoms and Pd sub‐nano clusters on the surface of γ‐Al2O3. Pd/Al2O3‐4 as an adsorbent is evaluated using the benzene ultra‐deep desulfurization procedure, wherein thiophene is used as a probe molecule. The sulfur adsorption capacity of Pd/Al2O3‐4 is 1.76 mg g−1 for the ultra‐deep adsorptive desulfurization of benzene at a sulfur concentration of 50 ppm. The sulfur adsorption capacity of the new Pd/Al2O3‐4 adsorbent is 21.8% higher than that of a commercial Pd/Al2O3 adsorbent. In addition, the stability and durability of Pd/Al2O3‐4 are investigated at a sulfur concentration of 1 ppm. The Pd/Al2O3‐4 adsorbent achieves ≈100% thiophene removal after 434 h, which is 62 h more than the time required by the commercial Pd/Al2O3 adsorbent. The novel Pd precursor shows excellent potential for industrial applications, and the Pd/Al2O3‐4 adsorbent can be produced on a mass scale of 500 kg per batch.

show abstract

“…Moreover, using ceria (CeO 2 ), zirconia (ZrO 2 ), or tin oxide (SnO 2 ) as support material was reported to reduce the negative impact of water (Ciuparu et However, choosing appropriate engine operation strategies can signi cantly contribute to maintaining high pollutant conversion rates as well. For instance, high-frequency lean-rich cycling, so-called dithering, can enhance pollutant conversion particularly in the low-temperature regime -a concept that is known for stoichiometric applications since decades (Hegedus et al 1980, Muraki andFujitani 1986) and that currently enjoys growing popularity again (Deka et al 2023, Roger et al 2023, Hodonj et al 2024). Similarly, periodic cycling between lean and short rich exhausts can increase the CH 4 oxidation activity of lean-operated Pd catalysts in humid exhausts, presumably by decomposition of adsorbed hydroxyl species during the rich phase along with an optimization of the oxidation state and morphology of the noble metal particles (Bounechada et al 2012, Ferri et al 2018, Karinshak et al 2020, Franken et al 2021).…”

Section: Introductionmentioning

confidence: 99%

Innovative Engine Test Bench Setup for Testing of Exhaust Gas Aftertreatment and detailed Gas Species Analysis for CNG-SI-Operation

Tomin,

Keller,

Wagner

et al. 2024

Preprint

View full text Add to dashboard Cite

For an efficient reduction of methane slip, a precise understanding of exhaust gas aftertreatment under real conditions is essential. Since it is not possible to produce catalytic converters in near-series geometry on a laboratory scale, it is necessary to resort to significantly smaller sample catalysts. Therefore, an engine test bench was designed to ensure real operating conditions for such samples with the help of space velocity and temperature control. A comparison between the actual and reference values of the space velocity results in a small deviation of 0.1% on average. Furthermore, the pressure conditions at the catalyst have been measured showing a propagation of pressure oscillations from the engine outlet which in combination with the space velocity regulation show that real conditions could be applied to the catalyst sample. Subsequently the exhaust gas concentrations were monitored with a Fourier transform infrared spectrometer. The catalyst material used is Pd on Al2O3 common for methane oxidation. The measurements show that the CH4 conversion is higher under lean conditions, but is below complete conversion. In a final comparison between purely stoichiometric operation and dithering, the course of the CH4 conversion rate over the test period is examined more closely. In addition to sampling pre- and post-catalyst, the exhaust gas composition is measured spatially resolved within a catalyst channel using special measurement technology. In the temporal course of the CH4 emissions, a stabilising effect due to the change of the operating mode can be seen showing that dithering seems to prevent further deactivation.

show abstract

Assessing the effect of O2 dithering on CH4 oxidation on Pd/Al2O3

Cited by 12 publications

References 36 publications

Review and Perspectives of Enhancement in the Catalytic Stability for the Complete Combustion of CO, CH₄, and Volatile Organic Compounds

Review and Perspectives of Enhancement in the Catalytic Stability for the Complete Combustion of CO, CH₄, and Volatile Organic Compounds

A Novel Pd Precursor Loaded γ‐Al₂O₃ with Excellent Adsorbent Performance for Ultra‐Deep Adsorptive Desulfurization of Benzene

Innovative Engine Test Bench Setup for Testing of Exhaust Gas Aftertreatment and detailed Gas Species Analysis for CNG-SI-Operation

Contact Info

Product

Resources

About

Assessing the effect of O2 dithering on CH4 oxidation on Pd/Al2O3

Cited by 12 publications

References 36 publications

Review and Perspectives of Enhancement in the Catalytic Stability for the Complete Combustion of CO, CH4, and Volatile Organic Compounds

Review and Perspectives of Enhancement in the Catalytic Stability for the Complete Combustion of CO, CH4, and Volatile Organic Compounds

A Novel Pd Precursor Loaded γ‐Al2O3 with Excellent Adsorbent Performance for Ultra‐Deep Adsorptive Desulfurization of Benzene

Innovative Engine Test Bench Setup for Testing of Exhaust Gas Aftertreatment and detailed Gas Species Analysis for CNG-SI-Operation

Contact Info

Product

Resources

About

Review and Perspectives of Enhancement in the Catalytic Stability for the Complete Combustion of CO, CH₄, and Volatile Organic Compounds

Review and Perspectives of Enhancement in the Catalytic Stability for the Complete Combustion of CO, CH₄, and Volatile Organic Compounds

A Novel Pd Precursor Loaded γ‐Al₂O₃ with Excellent Adsorbent Performance for Ultra‐Deep Adsorptive Desulfurization of Benzene