Atomic Structure and Valence State of Cobalt Nanocrystals on Carbon under Syngas Versus Hydrogen Reduction
(2022) In Journal of Physical Chemistry C 126(14). p.6325-6333- Abstract
The composition of the reducing gas in the activation of Co Fischer-Tropsch synthesis catalysts determines the nature of the catalytically active Co species. This study reports on the effect of H2versus syngas (H2/CO = 2) on the reducibility of Co3O4nanoparticles supported on hollow carbon spheres, using ex situ and in situ high-resolution aberration-corrected analytical electron microscopy. High-resolution images revealed twinned fcc Co particles encapsulated in carbon from syngas treatment while H2-treated particles were mostly CoO. Moreover, the electron energy loss of the Co-L3,2and O-K edge fine structures show improved reducibility in syngas than in H2at... (More)
The composition of the reducing gas in the activation of Co Fischer-Tropsch synthesis catalysts determines the nature of the catalytically active Co species. This study reports on the effect of H2versus syngas (H2/CO = 2) on the reducibility of Co3O4nanoparticles supported on hollow carbon spheres, using ex situ and in situ high-resolution aberration-corrected analytical electron microscopy. High-resolution images revealed twinned fcc Co particles encapsulated in carbon from syngas treatment while H2-treated particles were mostly CoO. Moreover, the electron energy loss of the Co-L3,2and O-K edge fine structures show improved reducibility in syngas than in H2at 350 °C. The effect of high temperature on the reducibility of the Co3O4nanoparticles is also explored. Carbon fiber encapsulation of twinned fcc Co particles observed during the syngas treatment provides sinter resistance at high temperatures. Both ex situ and in situ results indicate that syngas activation is efficient for obtaining highly reduced Co nanoparticles at lower temperatures.
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- author
- Makgae, Ofentse A. LU ; Phaahlamohlaka, Tumelo N. ; Yao, Benzhen ; Schuster, Manfred E. ; Slater, Thomas J.A. ; Edwards, Peter P. ; Coville, Neil J. ; Liberti, Emanuela and Kirkland, Angus I.
- organization
- publishing date
- 2022-04-14
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Physical Chemistry C
- volume
- 126
- issue
- 14
- pages
- 9 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85128220766
- ISSN
- 1932-7447
- DOI
- 10.1021/acs.jpcc.2c00482
- language
- English
- LU publication?
- yes
- id
- d5ab85a5-f08c-41fd-98ac-e2eacc20b8d0
- date added to LUP
- 2022-07-05 14:17:07
- date last changed
- 2023-11-19 08:38:27
@article{d5ab85a5-f08c-41fd-98ac-e2eacc20b8d0, abstract = {{<p>The composition of the reducing gas in the activation of Co Fischer-Tropsch synthesis catalysts determines the nature of the catalytically active Co species. This study reports on the effect of H<sub>2</sub>versus syngas (H<sub>2</sub>/CO = 2) on the reducibility of Co<sub>3</sub>O<sub>4</sub>nanoparticles supported on hollow carbon spheres, using ex situ and in situ high-resolution aberration-corrected analytical electron microscopy. High-resolution images revealed twinned fcc Co particles encapsulated in carbon from syngas treatment while H<sub>2</sub>-treated particles were mostly CoO. Moreover, the electron energy loss of the Co-L<sub>3,2</sub>and O-K edge fine structures show improved reducibility in syngas than in H<sub>2</sub>at 350 °C. The effect of high temperature on the reducibility of the Co<sub>3</sub>O<sub>4</sub>nanoparticles is also explored. Carbon fiber encapsulation of twinned fcc Co particles observed during the syngas treatment provides sinter resistance at high temperatures. Both ex situ and in situ results indicate that syngas activation is efficient for obtaining highly reduced Co nanoparticles at lower temperatures.</p>}}, author = {{Makgae, Ofentse A. and Phaahlamohlaka, Tumelo N. and Yao, Benzhen and Schuster, Manfred E. and Slater, Thomas J.A. and Edwards, Peter P. and Coville, Neil J. and Liberti, Emanuela and Kirkland, Angus I.}}, issn = {{1932-7447}}, language = {{eng}}, month = {{04}}, number = {{14}}, pages = {{6325--6333}}, publisher = {{The American Chemical Society (ACS)}}, series = {{Journal of Physical Chemistry C}}, title = {{Atomic Structure and Valence State of Cobalt Nanocrystals on Carbon under Syngas Versus Hydrogen Reduction}}, url = {{http://dx.doi.org/10.1021/acs.jpcc.2c00482}}, doi = {{10.1021/acs.jpcc.2c00482}}, volume = {{126}}, year = {{2022}}, }