Coprecipitated Ni-Alumina and Ni-Cu-Alumina Catalysts of Methane Decomposition and Carbon Deposition. II. Evolution of the Catalysts in Reaction Full article
Journal |
Applied Catalysis A: General
ISSN: 0926-860X , E-ISSN: 1873-3875 |
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Output data | Year: 1996, Volume: 141, Number: 1-2, Pages: 117-129 Pages count : 13 DOI: 10.1016/0926-860X(96)00026-9 | ||
Tags | Bimetallic Ni-Cu catalysts, Extended X-ray absorption fine structure spectroscopy, Filamentous carbon, Methane decomposition, Ni-alumina catalysts | ||
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Abstract:
Using coprecipitated Ni-alumina and NiCu-alumina catalysts, up to 250 g/gcat of filamentous carbon was produced by methane decomposition at 823 K and a methane pressure of 100 kPa. The process evolved three general stages. In the induction period carbon was dissolved into the Ni particles as evidenced by in situ X-ray powder diffraction measurements. This promoted the formation of large metal particles pear-shaped in Ni catalysts and quasi-octahedral in NiCu ones. The steady-state growth of the filaments occurred on the second stage. Finally, the catalyst was deactivated producing porous granules composed of interlaced long carbon filaments. In deactivated Ni catalysts the nickel was found in metal state, while in NiCu samples about half of the nickel was atomically dispersed in carbon as revealed by extended X-ray absorption fine structure spectroscopy. The deactivation of the catalysts was suggested to include the fragmentation of the metal particles as well as an atomic erosion in NiCu samples. In addition, in both catalysts the filaments growth could also be limited when the close-packed structures of porous carbon were achieved.
Cite:
Avdeeva L.B.
, Goncharova O.V.
, Kochubey D.I.
, Zaikovskii V.I.
, Plyasova L.M.
, Novgorodov B.N.
, Shaikhutdinov S.K.
Coprecipitated Ni-Alumina and Ni-Cu-Alumina Catalysts of Methane Decomposition and Carbon Deposition. II. Evolution of the Catalysts in Reaction
Applied Catalysis A: General. 1996. V.141. N1-2. P.117-129. DOI: 10.1016/0926-860X(96)00026-9 WOS Scopus РИНЦ
Coprecipitated Ni-Alumina and Ni-Cu-Alumina Catalysts of Methane Decomposition and Carbon Deposition. II. Evolution of the Catalysts in Reaction
Applied Catalysis A: General. 1996. V.141. N1-2. P.117-129. DOI: 10.1016/0926-860X(96)00026-9 WOS Scopus РИНЦ
Dates:
Submitted: | Sep 20, 1995 |
Accepted: | Jan 16, 1996 |
Published print: | Jul 4, 1996 |
Published online: | Aug 31, 1998 |
Identifiers:
Web of science | WOS:A1996UW51500008 |
Scopus | 2-s2.0-30244441163 |
Elibrary | 13234742 |
Chemical Abstracts | 1996:347232 |
Chemical Abstracts (print) | 125:90488 |
OpenAlex | W2037294913 |