Tuning the Basic Properties of ZnAl Hydrotalcites Modified with Ce Applied to Transesterification of Soybean Oil
Por:
Cabrera-Munguia, Denis A., Gonzalez, Horacio, Barreto-Gutierrez, Monica, Gutierrez-Alejandre, Aida, Rico, Jose L., Solis-Casados, Dora A.
Publicada:
1 jul 2020
Resumen:
The basicity of ZnAl hydrotalcite type materials was modified through
the incorporation of Ce into their structure and used as heterogeneous
catalysts in the transesterification of soybean oil. A series of novel
ZnAl-Ce(X) catalysts was synthesized by the co-precipitation method
varying the loading of Ce (X = Ce/Al molar ratio). The larger ionic
radius of Ce3+ (1.01 angstrom) compared with Al3+ (0.53 angstrom) and
Zn2+ (0.72 angstrom), hinders the appropriate incorporation of Ce3+ in
the brucite-like structure, causing a small segregation of Ce3+ as CeO2.
However, the concentration of basic sites (acid-basic Lewis pairs) and
specific surface area of the ZnAl-Ce(0.0) sample were enhanced with the
incorporation of Ce, improving its catalytic activity. The most
appropriate Ce loading was obtained with a Ce/Al molar ratio of 0.03,
which was attributed to its large surface area, along with a higher
amount of acid-basic Lewis pairs related to the presence of aluminum in
pentahedral coordination. Thus, the total amount of basic sites (-OH and
M-O-) of ZnAl-Ce(0.03) was triplicated, leading to a FAME yield of 80%
with this catalyst, which represents an increase of 11.3% when compared
with the ZnAl hydrotalcite without Ce.
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Filiaciones:
Cabrera-Munguia, Denis A.:
Univ Autonoma Coahuila, Fac Ciencias Quim, Saltillo 25280, Coahuila, Mexico
Gonzalez, Horacio:
Univ Michoacana, Fac Ingn Quim, Morelia 58030, Michoacan, Mexico
Barreto-Gutierrez, Monica:
Univ Michoacana, Fac Ingn Quim, Morelia 58030, Michoacan, Mexico
Gutierrez-Alejandre, Aida:
Univ Nacl Autonoma Mexico, UNICAT, De Ingn Quim, Fac Quim, Mexico City 04510, DF, Mexico
Rico, Jose L.:
Univ Michoacana, Fac Ingn Quim, Morelia 58030, Michoacan, Mexico
Solis-Casados, Dora A.:
UAEM UNAM, Ctr Conjunto Invest Quim Sustentable, Toluca 50200, Mexico
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