Function of Brønsted and Lewis acid sites in xylose conversion into furfural
Por:
Cabrera-Munguia, Denis A., Gutierrrez-Alejandre, Aida, Romero-Galarza, Adolfo, Morales-Martinez, Thelma K., Rios-Gonzalez, Leopoldo J., Sifuentes-Lopez, Jesus
Publicada:
18 oct 2023
Resumen:
In this work, the xylose conversion and the selectivity to furfural were
assessed over mesoporous sulfonic silica SBA-15-(X)SO3H catalysts doped
with metal ions (X = Al(iii), Ti(iv) or Zr(iv)). The type and amount of
acid sites were analyzed by adsorption of pivalonitrile. The
SBA-15-(X)SO3H materials show Lewis acid sites (LAS) and two types of
Bronsted acid sites (BAS) with different strengths. Type I (BAS I)
belongs to terminal silanol groups, type II (BAS II) is ascribed to
hydroxyl groups bonded to sulfur or transition metal, and the LAS is
related to M-O bonds. Optimal reaction conditions for the most active
catalyst (SBA-15-(Zr)SO3H) were 120 minutes of reaction at 160 degrees
C, 20 wt% of catalyst, and 2.5% of xylose/solvent. Additionally, a
kinetic study was carried out to calculate the rate constants, the
activation energy, and the pre-exponential factor for the xylose
dehydration reaction. It was found that the selectivity to furfural in
sulfonic silica SBA-15-(X)SO3H catalysts was directly related to the BAS
II fraction. While LAS negatively impacts the selectivity to furfural
leading to the undesired reaction between furfural and xylose obtaining
humins as secondary products.
In this work, the xylose conversion and the selectivity to furfural were
assessed over mesoporous sulfonic silica SBA-15-(X)SO3H catalysts doped
with metal ions (X = Al(iii), Ti(iv) or Zr(iv)).
Filiaciones:
Cabrera-Munguia, Denis A.:
Univ Autonoma Coahuila, Fac Ciencias Quim, CONACYT, Ing J Cardenas S-N, Saltillo 25280, Coahuila, Mexico
Gutierrrez-Alejandre, Aida:
UNAM, Dept Ingn Quim, UNICAT, Fac Quim, Ciudad De Mexico 04510, Mexico
Romero-Galarza, Adolfo:
Univ Autonoma Coahuila, Fac Ciencias Quim, CONACYT, Ing J Cardenas S-N, Saltillo 25280, Coahuila, Mexico
Morales-Martinez, Thelma K.:
Univ Autonoma Coahuila, Fac Ciencias Quim, CONACYT, Ing J Cardenas S-N, Saltillo 25280, Coahuila, Mexico
Rios-Gonzalez, Leopoldo J.:
Univ Autonoma Coahuila, Fac Ciencias Quim, CONACYT, Ing J Cardenas S-N, Saltillo 25280, Coahuila, Mexico
Sifuentes-Lopez, Jesus:
Univ Autonoma Coahuila, Fac Ingn Mecan & Elect, Carretera Torreón Matamoros km 7-5 CU, Torreon 27087, Coahuila, Mexico
gold, Gold
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