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Sulfidation of Supported Ni, Mo and NiMo Catalysts Studied by In Situ XAFS

Gajdek, Dorotea LU ; Jensen, Lucy Idowu Ajakaiye LU ; Briois, Valérie ; Hulteberg, Christian LU orcid ; Merte, Lindsay R. LU and Blomberg, Sara LU (2023) In Topics in Catalysis 66(17-18). p.1287-1295
Abstract

Active sites in Mo-based hydrotreating catalysts are produced by sulfidation. To achieve insights that may enable optimization of the catalysts, this process should be studied in situ. Herein we present a comparative XAFS study where the in situ sulfidation of Mo/δ-Al2O3 and Ni/δ-Al2O3 is compared to that of δ-Al2O3 supported NiMo catalysts with different NiMo ratios. The study also covers the comparison of sulfidation of Ni and Mo using different oxide supports as well as the sulfidation conditions applied in the reactor. The XAFS spectra confirms the oxide phase for all catalysts at the beginning of the sulfidation reaction and their conversion to a sulfidized phase is... (More)

Active sites in Mo-based hydrotreating catalysts are produced by sulfidation. To achieve insights that may enable optimization of the catalysts, this process should be studied in situ. Herein we present a comparative XAFS study where the in situ sulfidation of Mo/δ-Al2O3 and Ni/δ-Al2O3 is compared to that of δ-Al2O3 supported NiMo catalysts with different NiMo ratios. The study also covers the comparison of sulfidation of Ni and Mo using different oxide supports as well as the sulfidation conditions applied in the reactor. The XAFS spectra confirms the oxide phase for all catalysts at the beginning of the sulfidation reaction and their conversion to a sulfidized phase is followed with in situ measurements. Furthermore, it is found that the monometallic catalysts are less readily sulfidized than bimetallic ones, indicating the importance of Ni-Mo interactions for catalyst activation. Mo K-edge XAFS spectra did not show any difference related to the support of the catalyst or the pressure applied during the reaction. Ni K-edge XAFS spectra, however, show a more complete sulfidation of the Ni species in the catalyst when SiO2 is used as a support as compared to the Al2O3. Nevertheless, it is believed that stronger interactions with Al2O3 support prevent sintering of the catalyst which leads to its stabilization. The results contribute to a better understanding of how different parameters affect the formation of the active phase of the NiMo catalysts used in the production of biofuel.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bimetallic catalysts, Industrial catalysts, NiMo catalyst, Sulfidation, X-ray techniques, XAFS
in
Topics in Catalysis
volume
66
issue
17-18
pages
1287 - 1295
publisher
Springer
external identifiers
  • scopus:85146396385
ISSN
1022-5528
DOI
10.1007/s11244-023-01781-z
language
English
LU publication?
yes
id
c9419dbb-de8c-445e-be2a-a205ebcfb062
date added to LUP
2023-02-20 08:33:54
date last changed
2023-12-20 00:04:23
@article{c9419dbb-de8c-445e-be2a-a205ebcfb062,
  abstract     = {{<p>Active sites in Mo-based hydrotreating catalysts are produced by sulfidation. To achieve insights that may enable optimization of the catalysts, this process should be studied in situ. Herein we present a comparative XAFS study where the in situ sulfidation of Mo/δ-Al<sub>2</sub>O<sub>3</sub> and Ni/δ-Al<sub>2</sub>O<sub>3</sub> is compared to that of δ-Al<sub>2</sub>O<sub>3</sub> supported NiMo catalysts with different NiMo ratios. The study also covers the comparison of sulfidation of Ni and Mo using different oxide supports as well as the sulfidation conditions applied in the reactor. The XAFS spectra confirms the oxide phase for all catalysts at the beginning of the sulfidation reaction and their conversion to a sulfidized phase is followed with in situ measurements. Furthermore, it is found that the monometallic catalysts are less readily sulfidized than bimetallic ones, indicating the importance of Ni-Mo interactions for catalyst activation. Mo K-edge XAFS spectra did not show any difference related to the support of the catalyst or the pressure applied during the reaction. Ni K-edge XAFS spectra, however, show a more complete sulfidation of the Ni species in the catalyst when SiO<sub>2</sub> is used as a support as compared to the Al<sub>2</sub>O<sub>3</sub>. Nevertheless, it is believed that stronger interactions with Al<sub>2</sub>O<sub>3</sub> support prevent sintering of the catalyst which leads to its stabilization. The results contribute to a better understanding of how different parameters affect the formation of the active phase of the NiMo catalysts used in the production of biofuel.</p>}},
  author       = {{Gajdek, Dorotea and Jensen, Lucy Idowu Ajakaiye and Briois, Valérie and Hulteberg, Christian and Merte, Lindsay R. and Blomberg, Sara}},
  issn         = {{1022-5528}},
  keywords     = {{Bimetallic catalysts; Industrial catalysts; NiMo catalyst; Sulfidation; X-ray techniques; XAFS}},
  language     = {{eng}},
  number       = {{17-18}},
  pages        = {{1287--1295}},
  publisher    = {{Springer}},
  series       = {{Topics in Catalysis}},
  title        = {{Sulfidation of Supported Ni, Mo and NiMo Catalysts Studied by In Situ XAFS}},
  url          = {{http://dx.doi.org/10.1007/s11244-023-01781-z}},
  doi          = {{10.1007/s11244-023-01781-z}},
  volume       = {{66}},
  year         = {{2023}},
}