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Changes of crystalline phase and catalytic properties by cation substitution in mirror plane of hexaaluminate compounds

Journal Article · · Journal of Solid State Chemistry
; ;  [1]
  1. Kyushu Univ., Fukuoka (Japan); and others

Mn-substituted hexaaluminate compounds have been investigated as catalysts for high temperature combustion above 1000{degrees}C. In this study, changes of crystalline phase and catalytic properties of Sr{sub 1-x}Ln{sub x}MnAl{sub 11}O{sub 19-{alpha}}(Ln=Pr, Nd, Sm, Gd) were investigated. Two kinds of hexaaluminate phases existed as equilibrium phases in the unsubstituted sample, the Ln ions were preferentially soluble in one of these phases. Accompanied with the dissolution, unequilibrium LnAlO{sub 3} phase was sometimes formed for high x samples. The amount of this phase decreases with an increase in temperature and/or ionic radius of Ln. The surface area of the samples generally decreased with increasing extent of Ln substitution. Catalytic activity for methane combustion at low conversion level was improved by the substitution.

OSTI ID:
223717
Journal Information:
Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 121; ISSN 0022-4596; ISSN JSSCBI
Country of Publication:
United States
Language:
English