In:
International Journal of Materials Research, Walter de Gruyter GmbH, Vol. 103, No. 12 ( 2012-12-01), p. 1488-1498
Abstract:
The phase composition and defect structure of the system Li 2 O–MgO was investigated in terms of the long term stability of Li/MgO catalysts. The Li content was varied from 0 to 7 mol.%. Pure Li · MgO solid solutions were prepared via a special washing procedure. Li contents below 0.04 wt.% were stabilized within the MgO host lattice, whereas higher Li contents were found to segregate as Li 2 O and Li 2 CO 3 phases. The catalytic activity in the oxidative coupling of methane was found to decay for all catalysts over a period of 19 h on stream, accompanied by a loss of Li as LiOH. Li in the Li · MgO solid solution was found to be more stable in the lattice than in the surface region of the solid. However, impedance measurements on transition metal stabilized Li/MgO catalysts indicated that even the Li ions within the Li · MgO solid solution are not sufficiently stabilized. Thus, neither the Li compounds nor the dissolved Li ions within the Li/MgO solution seem to be truly stable at 750°C under catalytic conditions.
Type of Medium:
Online Resource
ISSN:
2195-8556
,
1862-5282
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2012
detail.hit.zdb_id:
2232675-3
detail.hit.zdb_id:
2128058-7
detail.hit.zdb_id:
203021-4
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