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The effect of Nb 2 O 5 and ZrO 2 additions on the behaviour of Li/MgO and Li/Na/MgO catalysts for the oxidative coupling of methane
Author(s) -
Mcnamara D. J.,
Korf S. J.,
Seshan K.,
Van Ommen J. G.,
Ross J. R. H.
Publication year - 1991
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450690410
Subject(s) - ternary operation , catalysis , selectivity , oxidative coupling of methane , inorganic chemistry , oxide , metal , transition metal , ternary compound , materials science , chemistry , ternary numeral system , metallurgy , organic chemistry , computer science , programming language
Incorporation of Nb 2 O 5 or ZrO 2 into both Li/MgO and Li/Na/MgO systems produced ternary and quaternary catalysts, respectively, capable of attaining optimal C 2 yields and selectivities at lower temperatures relative to the unpromoted materials. The degree of enhancement effected by these metal oxide additives was compared to that produced by Li/MgO and Li/Na/MgO catalysts promoted with SnO 2 or Co 3 O 4 . At reaction temperatures < 700°C, the Li/Co/MgO ternary system showed marked differences in behaviour compared to the other ternary catalysts tested. This was particularly evident in the variation in C 2 selectivity with time on stream during ageing studies of (i) untreated materials, (ii) materials pretreated in CO 2 , and (iii) materials dosed periodically with CHCI 3 .