INCAPE   05401
INSTITUTO DE INVESTIGACIONES EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Unidad Ejecutora - UE
artículos
Título:
"MgO-based catalysts for monoglyceride synthesis from methyl oleate and glycerol: Effect of Li promotion"
Autor/es:
C.A. FERRETTI; C.R. APESTEGU¨ªA; J.I. DI COSIMO
Revista:
APPLIED CATALYSIS A-GENERAL
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2011 vol. 399 p. 146 - 153
ISSN:
0926-860X
Resumen:
The synthesis of monoglycerides (glyceryl monooleates) by heterogeneously catalyzed glycerolysis of
an unsaturated fatty acid methyl ester (methyl oleate) was studied on MgO and Li-promoted MgO
catalysts.
Several MgO-based catalysts with different Li loadings were prepared by incipient wetness impregnation
and characterized by XRD, N2 physisorption, and FTIR and TPD of CO2 among other techniques.
Promotion of MgO with lithium, a basic promoter, affected the textural and structural properties of
the resulting oxides so that more crystalline MgO phases with decreased surface area were obtained
at increasing Li contents. Furthermore, the addition of Li generated new strong base sites because of
formation of dispersed surface Li2O species, and thereby increased the total base site density of parent
MgO.
Li-containing MgO catalysts efficiently promoted the glycerolysis reaction, achieving high monoglyceride
yields (70¨C73%) at 493 K. The initial monoglyceride formation rate increased linearly with the Li
content on the sample following the enhanced overall catalyst base strength. Although conversions at the
end of the run were ¡Ö100% for all the catalysts, the monoglyceride selectivity slightly decreased with the
Li loading, probably as a consequence of the less surface affinity for glycerol adsorption that facilitates
competing monoglyceride re-adsorption and transformation to diglycerides by consecutive glycerolysis
or disproportionation reactions.2 physisorption, and FTIR and TPD of CO2 among other techniques.
Promotion of MgO with lithium, a basic promoter, affected the textural and structural properties of
the resulting oxides so that more crystalline MgO phases with decreased surface area were obtained
at increasing Li contents. Furthermore, the addition of Li generated new strong base sites because of
formation of dispersed surface Li2O species, and thereby increased the total base site density of parent
MgO.
Li-containing MgO catalysts efficiently promoted the glycerolysis reaction, achieving high monoglyceride
yields (70¨C73%) at 493 K. The initial monoglyceride formation rate increased linearly with the Li
content on the sample following the enhanced overall catalyst base strength. Although conversions at the
end of the run were ¡Ö100% for all the catalysts, the monoglyceride selectivity slightly decreased with the
Li loading, probably as a consequence of the less surface affinity for glycerol adsorption that facilitates
competing monoglyceride re-adsorption and transformation to diglycerides by consecutive glycerolysis
or disproportionation reactions.2O species, and thereby increased the total base site density of parent
MgO.
Li-containing MgO catalysts efficiently promoted the glycerolysis reaction, achieving high monoglyceride
yields (70¨C73%) at 493 K. The initial monoglyceride formation rate increased linearly with the Li
content on the sample following the enhanced overall catalyst base strength. Although conversions at the
end of the run were ¡Ö100% for all the catalysts, the monoglyceride selectivity slightly decreased with the
Li loading, probably as a consequence of the less surface affinity for glycerol adsorption that facilitates
competing monoglyceride re-adsorption and transformation to diglycerides by consecutive glycerolysis
or disproportionation reactions.¡Ö100% for all the catalysts, the monoglyceride selectivity slightly decreased with the
Li loading, probably as a consequence of the less surface affinity for glycerol adsorption that facilitates
competing monoglyceride re-adsorption and transformation to diglycerides by consecutive glycerolysis
or disproportionation reactions.