E. Karaog˘lu et al. / Materials Research Bulletin 47 (2012) 2480–2486
2485
catalyst could be completely recovered with external magnetic
field. Which indicates that the magnetic catalyst is suitable for
recyclable heterogeneous catalysis applications.
NE
A3
A2
4. Conclusion
We report for the first time on a novel one-pot reflux route for
the fabrication of Piperidine-4-carboxylic acid (PPCA) functional-
ized Fe3O4 nanoparticles as a novel organic–inorganic hybrid
heterogeneous catalyst. Size evaluation via various techniques
revealed size of Fe3O4 particles around 10–11 nm with nearly
single crystalline character. Magnetization measurements showed
that Fe3O4–PPCA catalyst has a no coercivity and remanence
together with unsaturated magnetization at high field. Fe3O4–
PPCA catalyst possesses a high saturation magnetization (60 emu/
g) and it is recoverable by magnetic decantation and could be
reused several times without significant loss in catalytic activity
and selectivity for Knoevenagel reaction. Our method has the
advantage that no further modification of the magnetic particles is
necessary for utilization as catalyst. Further studies on the effects
of Fe3O4–PPCA catalyst on the catalytic activity for other catalyst
systems are in progress.
1725
A1
1550
1700
P3
Acknowledgements
P2
P1
The authors are thankful to the Fatih University, Research
Project Foundation (Contract no: P50020902-2).
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