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Abstract
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An efficient heterogeneous palladium catalyst
system has been developed based on immobilization of
Pd nanoparticles on silica-bonded N-propylpiperazine
(SBNPP) substrate. SBNPP substrate can stabilize the Pd
nanoparticles effectively so that it can improve their stability
against aggregation. Also, grafted piperazine species
onto the silica backbone prevents the removing of Pd
nanoparticles from the substrate surface. It seems that the
high recyclable capability of Pd-SBNPP catalysts is
resulted from these two characteristics. Transmission
electron microscopy (TEM) of catalyst is shown the size of
Pd nanoparticles in Pd-SBNPP average of 20 nm. Furthermore,
X-ray photoelectron spectroscopy (XPS) of Pd-
SBNPP is shown the presence of Pd(0) in the structure of
this catalyst. Overall, TEM, XPS and XRD experiments
strongly suggested that Pd nanoparticles were formed and
immobilized on silica-functionalized piperazine. The catalytic
activity of this catalyst was investigated in the Heck
and Suzuki reactions. The catalyst could be recycled several
times without appreciable loss in catalytic activity.
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