Effect of pH during ion exchange on catalyst properties and high-temperature methane oxidation over Fe-BEA zeolites
- 1Technical University of Munich, School of Natural Sciences, Lichtenbergstr. 4, 85748 Garching b. München, Germany; Technical University of Munich, Catalysis Research Center, Ernst-Otto-Fischer-Str. 1, 85748 Garching b. München, Germany
- 2Technical University of Munich, School of Natural Sciences, Lichtenbergstr. 4, 85748 Garching b. München, Germany; Technical University of Munich, Catalysis Research Center, Ernst-Otto-Fischer-Str. 1, 85748 Garching b. München, Germany; Corresponding author at: Technical University of Munich, School of Natural Sciences, Lichtenbergstr. 4, 85748 Garching b. München, Germany.
Abstract
Methane slip from natural gas-fueled systems remains an important environmental challenge due to the high global warming potential of methane. Catalytic oxidation is therefore critical for mitigating methane slip, but affordable, efficient, and stable catalysts remain a key challenge. Among transition-metal-based catalysts, Fe-containing zeolites are promising materials as they can stabilize a wide range of Fe species with distinct structural and redox properties. However, the influence of Fe speciation on high-temperature methane oxidation activity and selectivity remains insufficiently understood. In this work, the influence of pH during liquid ion exchange of Fe-containing BEA zeolites on the catalyst composition was investigated. Increasing the pH yielded higher Fe contents, while decreasing the degree of dealumination during ion exchange. The catalysts were characterized using structural and spectroscopic techniques to establish relationships between Fe loading, Fe speciation, accessibility, redox behavior, and catalytic performance. The results show that increasing Fe contents promote the formation of oligomeric Fe x O y species and Fe 2 O 3 nanoparticles in addition to isolated framework-associated Fe species. Catalytic evaluation of high-temperature methane oxidation revealed that Fe incorporation significantly improves the activity compared to the parent zeolite. The highest CH 4 consumption rate per total mole of Fe was correlated with high proportions of dispersed Fe species, suggesting that these species contribute most effectively to methane activation. In contrast, the catalyst containing a distinct α-Fe 2 O 3 phase exhibited a significantly higher CO 2 selectivity. Overall, these findings indicate a correlation between the loading-dependent Fe speciation and catalytic activity and selectivity of Fe-BEA catalysts during high-temperature methane oxidation.
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BibTeX
@article{niederdrank2026effect,
title = {{Effect of pH during ion exchange on catalyst properties and high-temperature methane oxidation over Fe-BEA zeolites}},
author = {Anne Niederdränk and Merle Blum and Jonas Kiefel and Melike Mechmed and Olaf Hinrichsen},
journal = {Applied Catalysis O: Open},
year = {2026},
month = oct,
doi = {10.1016/j.apcato.2026.207124},
url = {https://doi.org/10.1016/j.apcato.2026.207124},
note = {CC BY},
}
RIS
TY - JOUR
TI - Effect of pH during ion exchange on catalyst properties and high-temperature methane oxidation over Fe-BEA zeolites
AU - Anne Niederdränk
AU - Merle Blum
AU - Jonas Kiefel
AU - Melike Mechmed
AU - Olaf Hinrichsen
PY - 2026
DA - 2026/10/30
JO - Applied Catalysis O: Open
DO - 10.1016/j.apcato.2026.207124
UR - https://doi.org/10.1016/j.apcato.2026.207124
AB - Methane slip from natural gas-fueled systems remains an important environmental challenge due to the high global warming potential of methane. Catalytic oxidation is therefore critical for mitigating methane slip, but affordable, efficient, and stable catalysts remain a key challenge. Among transition-metal-based catalysts, Fe-containing zeolites are promising materials as they can stabilize a wide range of Fe species with distinct structural and redox properties. However, the influence of Fe speciation on high-temperature methane oxidation activity and selectivity remains insufficiently understood. In this work, the influence of pH during liquid ion exchange of Fe-containing BEA zeolites on the catalyst composition was investigated. Increasing the pH yielded higher Fe contents, while decreasing the degree of dealumination during ion exchange. The catalysts were characterized using structural and spectroscopic techniques to establish relationships between Fe loading, Fe speciation, accessibility, redox behavior, and catalytic performance. The results show that increasing Fe contents promote the formation of oligomeric Fe x O y species and Fe 2 O 3 nanoparticles in addition to isolated framework-associated Fe species. Catalytic evaluation of high-temperature methane oxidation revealed that Fe incorporation significantly improves the activity compared to the parent zeolite. The highest CH 4 consumption rate per total mole of Fe was correlated with high proportions of dispersed Fe species, suggesting that these species contribute most effectively to methane activation. In contrast, the catalyst containing a distinct α-Fe 2 O 3 phase exhibited a significantly higher CO 2 selectivity. Overall, these findings indicate a correlation between the loading-dependent Fe speciation and catalytic activity and selectivity of Fe-BEA catalysts during high-temperature methane oxidation.
SN - 2950-6484
ER -