TY - JOUR
T1 - Acidic ionic liquid immobilized on magnetic mesoporous silica
T2 - Preparation and catalytic performance in esterification
AU - Zhen, Bin
AU - Jiao, Qingze
AU - Zhang, Yaping
AU - Wu, Qin
AU - Li, Hansheng
PY - 2012/11/28
Y1 - 2012/11/28
N2 - Magnetic mesoporous silica (SCF) with cobalt ferrite nanoparticles embedded in silica, exhibiting a mesoporous structure, high magnetic responsivity and paramagnetism, was prepared using a reverse microemulsion-mediated sol-gel method and then modified with 3-mercaptopropyl trimethoxysilane to achieve sulfhydryl-group-modified SCF (MPS-SCF). 1-Allyl-3-(butyl-4-sulfonyl) imidazolium trifluoromethanesulfonate ([BsAIm][OTf]) was immobilized on MPS-SCF via free radical addition. The obtained MPS-SCF and [BsAIm][OTf]/SCF were characterized by FT-IR, XRD, TEM, VSM, elemental analysis and N2 adsorption-desorption measurements. The immobilization of [BsAIm][OTf] on MPS-SCF and the relationship between the sulfhydryl group (SH) loading of MPS-SCF and the ionic liquid loading of [BsAIm][OTf]/SCF were studied. The catalytic activities of [BsAIm][OTf]/SCF were evaluated through the esterification of oleic acid with straight-chain alcohols. The results showed that more modifications corresponded to an increase in the SH loading of MPS-SCF and a decrease in the average pore diameter and specific surface area of MPS-SCF. The more SH groups that were supported on MPS-SCF, the less ionic liquid was immobilized on [BsAIm][OTf]/SCF due to its smaller pore diameter, which hindered the diffusion and immobilization of [BsAIm][OTf]. Moreover, when the carbon number of the straight-chain alcohol increased, the mass-transfer resistance in [BsAIm][OTf]/SCF rapidly increased and the conversion of oleic acid significantly decreased under the same reaction conditions.
AB - Magnetic mesoporous silica (SCF) with cobalt ferrite nanoparticles embedded in silica, exhibiting a mesoporous structure, high magnetic responsivity and paramagnetism, was prepared using a reverse microemulsion-mediated sol-gel method and then modified with 3-mercaptopropyl trimethoxysilane to achieve sulfhydryl-group-modified SCF (MPS-SCF). 1-Allyl-3-(butyl-4-sulfonyl) imidazolium trifluoromethanesulfonate ([BsAIm][OTf]) was immobilized on MPS-SCF via free radical addition. The obtained MPS-SCF and [BsAIm][OTf]/SCF were characterized by FT-IR, XRD, TEM, VSM, elemental analysis and N2 adsorption-desorption measurements. The immobilization of [BsAIm][OTf] on MPS-SCF and the relationship between the sulfhydryl group (SH) loading of MPS-SCF and the ionic liquid loading of [BsAIm][OTf]/SCF were studied. The catalytic activities of [BsAIm][OTf]/SCF were evaluated through the esterification of oleic acid with straight-chain alcohols. The results showed that more modifications corresponded to an increase in the SH loading of MPS-SCF and a decrease in the average pore diameter and specific surface area of MPS-SCF. The more SH groups that were supported on MPS-SCF, the less ionic liquid was immobilized on [BsAIm][OTf]/SCF due to its smaller pore diameter, which hindered the diffusion and immobilization of [BsAIm][OTf]. Moreover, when the carbon number of the straight-chain alcohol increased, the mass-transfer resistance in [BsAIm][OTf]/SCF rapidly increased and the conversion of oleic acid significantly decreased under the same reaction conditions.
KW - Acidic ionic liquid
KW - Catalyst
KW - Esterification
KW - Magnetism
KW - Mesoporous silica
UR - http://www.scopus.com/inward/record.url?scp=84870366605&partnerID=8YFLogxK
U2 - 10.1016/j.apcata.2012.08.023
DO - 10.1016/j.apcata.2012.08.023
M3 - Article
AN - SCOPUS:84870366605
SN - 0926-860X
VL - 445-446
SP - 239
EP - 245
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
ER -