Synthesis of highly stable CoFe2O4 nanoparticles and their use as magnetically separable catalyst for Knoevenagel reaction in aqueous medium

Senapati, Kula Kamal; Borgohain, C.; Phukan, Prodeep

doi:10.1016/j.molcata.2011.02.007

Cited by 156 publications

(51 citation statements)

References 52 publications

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“…4. The spectrum for CoFe 2 O 4 agrees with previous results [39,40]. All the representative signals for CoFe 2 O 4 are observed in the XRD spectra of MNPs.…”

Section: Resultssupporting

confidence: 90%

Cellobiose hydrolysis using acid-functionalized nanoparticles

Peña

Ikenberry

Ware

et al. 2011

Biotechnol Bioproc E

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Mineral acids have been used effectively for the pretreatment of cellulosic biomass to improve sugar recovery and promote its conversion to ethanol; however, substantial capital investment is required to enable separation of the acid, and corrosion-resistant materials are necessary. Disposal and neutralization costs are also concerns because they can decrease the economic feasibility of the process. In this work, three acid-functionalized nanoparticles were synthesized for pretreatment and hydrolysis of lignocellulosic biomass. Silica-protected cobalt spinel ferrite nanoparticles were functionalized with perfluoroalkylsulfonic acid (PFS), alkylsulfonic acid (AS), and butylcarboxylic acid (BCOOH) groups. These nanoparticles were magnetically separated from the reaction media and reused. TEM images showed that the average diameter was 2 nm for both PFS and BCOOH nanoparticles and 7 nm for AS nanoparticles. FTIR confirmed the presence of sulfonic and carboxylic acid functional groups. Ion exchange titration measurements yielded 0.9, 1.7, and 0.2 mmol H + /g of catalyst for PFS, AS, and BCOOH nanoparticles, respectively. Elemental analysis results indicated that PFS and AS nanoparticles had 3.1 and 4.9% sulfur, respectively. Cellobiose hydrolysis was used as a model reaction to evaluate the performance of acid-functionalized magnetic nanoparticles for breaking β-(1→4) glycosidic bonds. Cellobiose conversion of 78% was achieved when using AS nanoparticles as the catalyst at 175°C for 1 h, which was significantly higher than the conversion for the control experiment (52%). AS nanoparticles retained more than 60% of their sulfonic acids groups after the first run, and 65 and 60% conversions were obtained for the second and third runs, respectively.

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“…4. The spectrum for CoFe 2 O 4 agrees with previous results [39,40]. All the representative signals for CoFe 2 O 4 are observed in the XRD spectra of MNPs.…”

Section: Resultssupporting

confidence: 90%

Cellobiose hydrolysis using acid-functionalized nanoparticles

Peña

Ikenberry

Ware

et al. 2011

Biotechnol Bioproc E

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“…After 1 h, the two catalysts gave quantitative yields of the condensation product in all of these experiments and no significant influence was observed for the type of the solvent used in these reactions. The activity of the two catalysts in the Knoevenagel condensation was similar to magnetically separable systems reported before [55][56][57][58][59].…”

Section: Catalytic Studies Of the Quasi-homogeneous And Heterogeneoussupporting

confidence: 85%

“…In kinetic studies, Jones et al found that CoFe 2 O 4 nanoparticles functionalized with a diamine group are even more efficient in Knoevenagel reactions than amino-functionalized porous silica catalysts [55]. Moreover, mesoporous Mg-Fe bi-metal oxides [58] and CoFe 2 O 4 [59] were recently reported as magnetically separable catalysts for Knoevenagel reactions.…”

Section: Open Accessmentioning

confidence: 99%

Magnetically Separable Base Catalysts: Heterogeneous Catalysis vs. Quasi-Homogeneous Catalysis

Abu‐Reziq

Alper

2012

Applied Sciences

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Abstract:The synthesis of magnetically separable quasi-homogeneous base catalyst and heterogeneous base catalyst is described. The quasi-homogeneous catalyst is achieved by supporting silane monomers functionalized with different amine groups directly on the surface of magnetite nanoparticles. The heterogeneous catalyst is prepared via a sol-gel process in which silane monomers containing different amine groups are copolymerized with tetraethoxysilane in the presence of magnetite nanoparticles functionalized with ionic liquid moieties. The reactivity of the quasi-homogeneous and the heterogeneous base catalysts is compared in the nitroaldol condensation.

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“…Nickel ferrite has inverse spinel structure [6]. Various methods are used to synthesize ferrite nanoparticles, such as: combustion, mechanochemical method, redox process, forced hydrolysis, co-precipitation, sol-gel, hydrothermal, polymer combustion method (PC), solid state method (SS), micro-emulsion, sonochemical, electrochemical and thermal decomposition method [7][8][9][10][11][12][13][14][15]. Among these, the combustion is one of the facile and one-step methods since it allows the preparation of nanocrystalline ferrites with an equiaxial shape, well-controlled morphology and narrow particle size distribution [16].…”

Section: Introductionmentioning

confidence: 99%

Nickel<span> ferrite </span>nanoparticle as a magnetic catalyst: Synthesis and dye degradation

Kar

Ghahari

Manteghi

2017

Proceedings of the 21st International Electronic Conference on Synthetic Organic Chemistry

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The aim of this work is the synthesis of NiFe 2 O 4 nanoparticles to catalyze photodegradation of direct red 264 under visible light. So, NiFe 2 O 4 nanoparticles were synthesized by a sol-gel autocombustion method. The catalyst was characterized by XRD, SEM, FT-IR and DRS. The effect of NiFe 2 O 4 nanoparticles as a catalyst was studied on photocatalytic degradation of Direct Red 264 (DR264) in typical wastewater using visible light irradiation. UV-vis spectrophotometer was used to measure concentration of dyes before and after degradation.

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Synthesis of highly stable CoFe2O4 nanoparticles and their use as magnetically separable catalyst for Knoevenagel reaction in aqueous medium

Cited by 156 publications

References 52 publications

Cellobiose hydrolysis using acid-functionalized nanoparticles

Cellobiose hydrolysis using acid-functionalized nanoparticles

Magnetically Separable Base Catalysts: Heterogeneous Catalysis vs. Quasi-Homogeneous Catalysis

Nickel<span> ferrite </span>nanoparticle as a magnetic catalyst: Synthesis and dye degradation

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