Assessing the effect of O&lt;sub&gt;2&lt;/sub&gt; dithering on CH&lt;sub&gt;4&lt;/sub&gt; oxidation on Pd/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;

Roger, M.; Kröcher, O.; Ferri, D.

doi:10.1016/j.cej.2022.138865

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

Citation

Roger, M., Kröcher, O., & Ferri, D. (2023). Assessing the effect of O₂ dithering on CH₄ oxidation on Pd/Al₂O₃. Chemical Engineering Journal, 451, 138865 (10 pp.). https://doi.org/10.1016/j.cej.2022.138865

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:45464

Under periodic lean/rich operation generated by repeated O₂ pulses (O₂-dithering), the abatement of CH₄ and NO is enhanced compared to static operation. However, it is not well understood how the dithering parameters (pulse amplitude and frequency) affect CH₄ conversion, making it difficult to anticipate the impact of such pulses on the catalytic performance. Here, we show that the effect of O₂-dithering on the activity of Pd/Al₂O₃ can be reliably assessed as a function of dithering parameters, temperature, and exhaust gas composition. Operando X-ray absorption spectroscopy was used to support the conclusions based on considerations of the Pd oxidation state. Our work relies on explicit calculations of the O₂ concentration present in the reactive feed, which is based on the amount of O₂ pulsed to the system and the pollutants’ conversion. Since NO contributes to the amount of oxygen available during reaction, its concentration and conversion need to be correctly evaluated.