Internal Field 59 Co NMR Study of Cobalt-Iron Nanoparticles During the Activation of CoFe2/CaO Catalyst for Carbon Nanotube Synthesis | Sciact - CRIS-system of Boreskov Institute of Catalysis

Internal Field 59 Co NMR Study of Cobalt-Iron Nanoparticles During the Activation of CoFe2/CaO Catalyst for Carbon Nanotube Synthesis Full article

Journal

Journal of Catalysis
ISSN: 0021-9517 , E-ISSN: 1090-2694

Output data

Year: 2018, Volume: 358, Pages: 62-70 Pages count : 9 DOI: 10.1016/j.jcat.2017.11.025

Tags

59Co NMR, Activation, Catalysts, Cobalt-iron alloy, Induction period, Multi-walled carbon nanotubes

Authors

Andreev Andrey S. ^1,2 , Krasnikov Dmitry V. ^1,3 , Zaikovskii Vladimir I. ^1,4 , Cherepanova Svetlana V. ^1,4 , Kazakova Mariya A. ^1,4 , Lapina Olga B. ^1,4 , Kuznetsov Vladimir L. ^1,5 , d'Espinose de Lacaillerie Jean–Baptiste ²

Affiliations

1	Boreskov Institute of Catalysis SB RAS (BIC SB RAS), Novosibirsk, pr. Lavrentieva, 5, 630090, Russia
2	École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), PSL Research University, Soft Matter Sciences and Engineering Laboratory, CNRS UMR 7615, 10 rue Vauquelin, F-75005 Paris, France
3	Skolkovo Institute of Science and Technology, Nobelya str. 3, Moscow 143025, Russia
4	Novosibirsk State University (NSU), Pirogova str., 2, Novosibirsk 630090, Russia
5	National University of Science and Technology (MISIS), Leninskiy ave. 4, Moscow 119049, Russia

Funding (4)

1	Federal Agency for Scientific Organizations	0303-2016-0002
2	Russian Foundation for Basic Research	17-53-150018
3	French Embassy in Moscow
4	The Ministry of Education and Science of the Russian Federation	К3-2017-040

CoFe2/CaO catalysts for multi-walled carbon nanotubes (MWCNT) were characterized during the activation period (T = 670 °C; C2H4/Ar = 1:1, 400 sccm) by internal field 59Co nuclear magnetic resonance. During this induction period, although C2H4 is already reacting, the MWCNT yield remains negligible. The NMR spectra of the catalysts revealed the occurrence of several structural and magnetic species. They were not detectable by conventional X-ray diffraction but the heterogeneity of the metal particles was corroborated by high-resolution transmission electronic microscopy coupled with energy dispersive X-ray spectroscopy. Two samples quenched at different activation time contained, beside non-reacted pure metal Co particles, strong and weak ferromagnetic alloys. During activation, the pure Co metal content dropped and an increase of the ordering of the cobalt-iron alloy in the catalyst was evidenced thus revealing a multistage activation mechanism for the reaction. We propose this ordering process during the induction period to be an intermediate step between the strong ferromagnetic Co rich alloy and the weak ferromagnetic Fe rich one and that it favors the onset of MWCNTs growth.

Andreev A.S. , Krasnikov D.V. , Zaikovskii V.I. , Cherepanova S.V. , Kazakova M.A. , Lapina O.B. , Kuznetsov V.L. , d'Espinose de Lacaillerie J.
Internal Field 59 Co NMR Study of Cobalt-Iron Nanoparticles During the Activation of CoFe2/CaO Catalyst for Carbon Nanotube Synthesis
Journal of Catalysis. 2018. V.358. P.62-70. DOI: 10.1016/j.jcat.2017.11.025 WOS Scopus РИНЦ ANCAN OpenAlex

Submitted:	Sep 8, 2017
Accepted:	Nov 22, 2017
Published online:	Dec 12, 2017
Published print:	Feb 1, 2018

Web of science:	WOS:000424718900008
Scopus:	2-s2.0-85037678185
Elibrary:	35479971
Chemical Abstracts:	2017:1913712
Chemical Abstracts (print):	169:57603
OpenAlex:	W2773503738

DB	Citing
Web of science	30
Scopus	32
Elibrary	31
OpenAlex	34