How Different Rare Earth Elements Influence PdO Stability in Catalysts

The catalytic combustion of methane is an important technology used for the production of clean energy as well as for after-exhaust treatment. The use of this in gas turbines (high temperature catalytic combustion or HTCC) results in very low emissions of unburned hydrocarbons, NOx and CO, whilst the application of a catalytic converter in vehicles fuelled by natural gas (low temperature catalytic combustion or LTCC) is essential to reduce unburned methane, which is considered to be a strong greenhouse gas.

Palladium Oxide

Amongst the range of materials which have been studied for catalytic combustion of methane, supported palladium oxide (PdO) is known to be the most active. This material, however, undergoes intense deactivation at increased temperatures due to the breakdown of PdO into metallic Pd.

In addition, reoxidation of Pd occurs at a much lower temperature, thereby resulting in a wide window of stability of less active Pd metal. This issue is of considerable interest when dealing with HTCC.

A number of studies have been carried out to identify appropriate promoters which have the required capacity to stabilize the oxide phase at elevated temperatures. This study has been particularly focussed on the screening of rare earth oxides that have been added onto alumina supports as PdO stabilizers.

Within this study, the effect of the addition of Pr, Ce, Tb and La on a Pd-alumina catalyst was examined. Temperature programmed combustion experiments were applied to monitor the catalytic performance of the various catalysts. These experiments were conducted in a standard lab-scale microreactor for powder analysis.

Hiden Analytical HPR-20 Mass Spectrometer

The Hiden Analytical HPR-20 mass spectrometer (Figure 1) was used for both qualitative and quantitative measurement of the effluent gases on the reactor’s downstream.Rare Earth Elements, PdO Stability, Catalysts

 

Figure 1. Hiden Analytical HPR-20 Mass Spectrometer in the Lab

The comparison of the curves indicating conversion of methane and/or production of CO2 was utilized to assess the effectiveness of the different formulations of the catalysts (Figure 2). On these curves, it was possible to distinguish the loss in conversion due to the decomposition of PdO, followed by a recovery due to the re-oxidation of Pd at lower temperature.

Methane conversion and/or CO2 production

Figure 2. Methane conversion and/or CO2 production

References

PROJECT SUMMARY BY: Sara Colussi & Alessandro Trovarelli Dipartimento di Chimica, Fisica e Ambiente, Università di Udine, via del Cotonificio 108, 33100 UDINE, ITALY.

PAPER REFERENCE: S. Colussi, A. Trovarelli, C. Cristiani, L. Lietti, G. Groppi (2012) “The influence of ceria and other rare earth promoters on palladium-based methane combustion catalysts” Catalysis Today 180 (1), 124-130

This information has been sourced, reviewed and adapted from materials provided by Hiden Analytical.

For more information on this source, please visit Hiden Analytical.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Hiden Analytical. (2021, December 17). How Different Rare Earth Elements Influence PdO Stability in Catalysts. AZoM. Retrieved on December 07, 2024 from https://www.azom.com/article.aspx?ArticleID=12225.

  • MLA

    Hiden Analytical. "How Different Rare Earth Elements Influence PdO Stability in Catalysts". AZoM. 07 December 2024. <https://www.azom.com/article.aspx?ArticleID=12225>.

  • Chicago

    Hiden Analytical. "How Different Rare Earth Elements Influence PdO Stability in Catalysts". AZoM. https://www.azom.com/article.aspx?ArticleID=12225. (accessed December 07, 2024).

  • Harvard

    Hiden Analytical. 2021. How Different Rare Earth Elements Influence PdO Stability in Catalysts. AZoM, viewed 07 December 2024, https://www.azom.com/article.aspx?ArticleID=12225.

Ask A Question

Do you have a question you'd like to ask regarding this article?

Leave your feedback
Your comment type
Submit

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.