Oxidation of dichloromethane over Au, Pt, and Pt-Au containing catalysts supported on γ-Al₂O₃ and CeO₂-Al₂O₃
Nevanperä, Tuomas K.; Pitkäaho, Satu; Ojala, Satu; Keiski, Riitta L. (2020-10-12)
Nevanperä, T.K.; Pitkäaho, S.; Ojala, S.; Keiski, R.L. Oxidation of Dichloromethane over Au, Pt, and Pt-Au Containing Catalysts Supported on γ-Al2O3 and CeO2-Al2O3. Molecules 2020, 25, 4644. https://doi.org/10.3390/molecules25204644
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
https://creativecommons.org/licenses/by/4.0/
https://urn.fi/URN:NBN:fi-fe2020111991964
Tiivistelmä
Abstract
Au, Pt, and Pt-Au catalysts supported on Al₂O₃ and CeO₂-Al₂O₃ were studied in the oxidation of dichloromethane (DCM, CH₂Cl₂). High DCM oxidation activities and HCl selectivities were seen with all the catalysts. With the addition of Au, remarkably lower light-off temperatures were observed as they were reduced by 70 and 85 degrees with the Al₂O₃-supported and by 35 and 40 degrees with the CeO₂-Al₂O₃-supported catalysts. Excellent HCl selectivities close to 100% were achieved with the Au/Al₂O₃ and Pt-Au/Al₂O₃ catalysts. The addition of ceria on alumina decreased the total acidity of these catalysts, resulting in lower performance. The 100-h stability test showed that the Pt-Au/Al₂O₃ catalyst was active and durable, but the selectivity towards the total oxidation products needs improvement. The results suggest that, with the Au-containing Al₂O₃-supported catalysts, DCM decomposition mainly occurs via direct DCM hydrolysis into formaldehyde and HCl followed by the oxidation of formaldehyde into CO and CO₂.
Kokoelmat
- Avoin saatavuus [34356]
