Temperature-Dependent Selectivity and Detection of Hidden Carbon Deposition in Methane Oxidation
(2024) In ACS Catalysis 14(8). p.5978-5986- Abstract
Reaction products in heterogeneous catalysis can be detected either on the catalyst surface or in the gas phase after desorption. However, if atoms are dissolved in the catalyst bulk, then reaction channels can become hidden. This is the case if the dissolution rate of the deposits is faster than their formation rate. This might lead to the underestimation or even overlooking of reaction channels such as, e.g., carbon deposition during hydrocarbon oxidation reactions, which is problematic as carbon can have a significant influence on the catalytic activity. Here, we demonstrate how such hidden deposition channels can be uncovered by carefully measuring the product formation rates in the local gas phase just above the catalyst surface... (More)
Reaction products in heterogeneous catalysis can be detected either on the catalyst surface or in the gas phase after desorption. However, if atoms are dissolved in the catalyst bulk, then reaction channels can become hidden. This is the case if the dissolution rate of the deposits is faster than their formation rate. This might lead to the underestimation or even overlooking of reaction channels such as, e.g., carbon deposition during hydrocarbon oxidation reactions, which is problematic as carbon can have a significant influence on the catalytic activity. Here, we demonstrate how such hidden deposition channels can be uncovered by carefully measuring the product formation rates in the local gas phase just above the catalyst surface with time-resolved ambient pressure X-ray photoelectron spectroscopy. As a case study, we investigate methane oxidation on a polycrystalline Pd catalyst in an oxygen-lean environment at a few millibar pressure. By ramping the temperature between 350 and 525 °C, we follow the time evolution of the different reaction pathways. Only in the oxygen mass-transfer limit do we observe CO production, while our data suggests that carbon deposition also happens outside this limit.
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- author
- Küst, Ulrike LU ; Wang, Weijia LU ; Wang, Changda ; Hagelin-Weaver, Helena ; Gustafson, Johan LU ; Shavorskiy, Andrey LU ; Weaver, Jason F. and Knudsen, Jan LU
- organization
- publishing date
- 2024-04-19
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- APXPS, carbon deposition, methane oxidation, palladium, time-resolved
- in
- ACS Catalysis
- volume
- 14
- issue
- 8
- pages
- 9 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:38660614
- scopus:85189959742
- ISSN
- 2155-5435
- DOI
- 10.1021/acscatal.4c00228
- language
- English
- LU publication?
- yes
- id
- 48087a69-18fd-4512-a559-62f57d495bdc
- date added to LUP
- 2024-05-02 14:00:03
- date last changed
- 2024-05-16 15:18:31
@article{48087a69-18fd-4512-a559-62f57d495bdc,
abstract = {{<p>Reaction products in heterogeneous catalysis can be detected either on the catalyst surface or in the gas phase after desorption. However, if atoms are dissolved in the catalyst bulk, then reaction channels can become hidden. This is the case if the dissolution rate of the deposits is faster than their formation rate. This might lead to the underestimation or even overlooking of reaction channels such as, e.g., carbon deposition during hydrocarbon oxidation reactions, which is problematic as carbon can have a significant influence on the catalytic activity. Here, we demonstrate how such hidden deposition channels can be uncovered by carefully measuring the product formation rates in the local gas phase just above the catalyst surface with time-resolved ambient pressure X-ray photoelectron spectroscopy. As a case study, we investigate methane oxidation on a polycrystalline Pd catalyst in an oxygen-lean environment at a few millibar pressure. By ramping the temperature between 350 and 525 °C, we follow the time evolution of the different reaction pathways. Only in the oxygen mass-transfer limit do we observe CO production, while our data suggests that carbon deposition also happens outside this limit.</p>}},
author = {{Küst, Ulrike and Wang, Weijia and Wang, Changda and Hagelin-Weaver, Helena and Gustafson, Johan and Shavorskiy, Andrey and Weaver, Jason F. and Knudsen, Jan}},
issn = {{2155-5435}},
keywords = {{APXPS; carbon deposition; methane oxidation; palladium; time-resolved}},
language = {{eng}},
month = {{04}},
number = {{8}},
pages = {{5978--5986}},
publisher = {{The American Chemical Society (ACS)}},
series = {{ACS Catalysis}},
title = {{Temperature-Dependent Selectivity and Detection of Hidden Carbon Deposition in Methane Oxidation}},
url = {{http://dx.doi.org/10.1021/acscatal.4c00228}},
doi = {{10.1021/acscatal.4c00228}},
volume = {{14}},
year = {{2024}},
}