Simultaneous pore enlargement and introduction of highly dispersed Fe active sites in MSNs for enhanced catalytic activity

Journal Article · Wed Feb 15 04:00:00 EST 2012 · Journal of Solid State Chemistry

OSTI ID:21612913

Xu, Dong ^[1]; Elangovan, S P ^[2]; Yongsheng, Li; Wenru, Zhao ^[1]; Iijima, Toshio; Yamazaki, Yasuo ^[2]

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1. Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)
2. Nippon Chemical Industries Co. Ltd., Tokyo 136-8515 (Japan)

An effective post-hydrothermal treatment strategy has been developed to dope highly dispersed iron catalytical centers into the framework of mesoporous silica, to keep the particle size in nanometric scale, and in the meanwhile, to expand the pore size of the synthesized mesoporous silica nanoparticles (MSNs). Characterization techniques such as XRD, BET, SEM and TEM support that the synthesized samples are long period ordered with particles size about 100 nm and a relatively large pore size of ca. 3.5 nm. UV-vis, XPS and EPR measurements demonstrate that the introduced iron active centers are highly dispersed in a coordinatively unsaturated status. NH{sub 3}-TPD verifies that the acid amount of iron-doped MSNs is quite high. The synthesized nanocatalysts show an excellent catalytic performance for benzylation of benzene by benzyl chloride, and they present relatively higher yield and selectivity to diphenylmethane with a lower iron content and much shorter reaction time. - Graphical abstract: Uniform MSNs with iron active centers and large pore size have been prepared by a newly developed strategy, which demonstrates enhanced catalytic performance for benzylation of benzene by benzyl chloride. Highlights: Black-Right-Pointing-Pointer Iron species were introduced into the framework of mesoporous silica nanoparticles with uniform dispersion. Black-Right-Pointing-Pointer The pore sizes of the synthesized nanocatalysts were expanded. Black-Right-Pointing-Pointer The acidic site quantities were quite high and the acidic centers were accessible. Black-Right-Pointing-Pointer The nanocatalysts presented higher yield and selectivity to diphenylmethane with significantly lower Fe content.

• OSTI ID: 21612913
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 186; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AMMONIA
AROMATICS
BENZENE
CATALYSTS
CHLORIDES
CHLORINE COMPOUNDS
COHERENT SCATTERING
DIFFRACTION
DOPED MATERIALS
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELECTRON SPIN RESONANCE
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
IRON
MAGNETIC RESONANCE
MATERIALS
METALS
MICROSCOPY
MINERALS
NANOSTRUCTURES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
ORGANIC COMPOUNDS
OXIDE MINERALS
PARTICLE SIZE
PARTICLES
PHOTOELECTRON SPECTROSCOPY
RESONANCE
SCANNING ELECTRON MICROSCOPY
SCATTERING
SILICA
SIZE
SPECTROSCOPY
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY