Catalysis Communications
journal homepage: www.elsevier.com/locate/catcom
Short Communication
Magnetically recyclable Fe@Pd/C as a highly active catalyst for Suzuki
coupling reaction in aqueous solution
Weijie Tang, Jing Li, Xiaodong Jin, Jian Sun, Jingwei Huang, Rong Li ⁎,1
Gansu Provincial Engineering Laboratory for Chemical Catalysis, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 5 July 2013
Received in revised form 29 August 2013
Accepted 2 September 2013
Available online 24 September 2013
In this work, a novel catalyst Fe@Pd/C was synthesized by sequential reduction method. The core–shell catalyst
exhibited efficient catalytic activity in Suzuki coupling reaction at mild condition in water. Moreover, the catalyst
could be recycled by external magnetic field and the yields achieved above 86% after reused at least 5 times.
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2013 Elsevier B.V. All rights reserved.
Keywords:
Fe@Pd/C catalyst
Core–shell
Suzuki coupling reaction
Aqueous solution
Magnetically recyclable
1
. Introduction
[16–19]. Traditionally, the reactions are conducted with homogeneous
catalysts, which are effective even with inactivated substrates and pro-
vide excellent turnover values [20]. In addition, most of the reaction me-
dium is organic solvent. In this case, some obvious weaknesses appear.
The employed organic solvents can be the source of environmental prob-
lems. Meanwhile, removing residual palladium and its ligands from the
reaction medium is usually a labor-intensive process [21], which restricts
the industrial reuse of these catalysts [22–27]. Therefore, we make a try
to use heterogeneous catalyst, a kind of excellent catalyst that is usually
inexpensive, readily obtained and easily removed from the reaction me-
dium compared with homogeneous catalyst.
On the basis of these observations, we report a simple and efficient
method for synthesizing carbon-supported Fe@Pd core–shell catalyst,
which can be sufficiently applied for Suzuki reaction in aqueous solu-
tion. It could be expected to not only obviously decrease the usage of
Pd but also improve yield and reusability compared with commercial
Pd/C catalyst.
Platinum-group metals, especially Pd, are excellent and versatile cat-
alysts in various important reactions such as carbon–carbon coupling
1], alcohol oxidation [2], olefin hydrogenation [3] and electrochemical
[
formic acid oxidation [4]. Pd nanoparticles (NPs) have been extensively
applied in these reactions due to their high surface-to-volume ratio and
ease of synthesis [5,6]. Unfortunately, catalytic reactions usually occur
on the surface of a Pd NP catalyst and a large fraction of Pd atoms in
the core are inactive [7]. Thus, it becomes a huge challenge that how
to take full advantage of Pd atoms and to reduce Pd usage without
sacrificing the catalytic performance. At present, the core–shell struc-
ture concept has been introduced to solve the difficulty and it has
sparked increasing attention for the application of bi-metallic catalysts
[8]. In this core–shell structure, the Pd is replaced by other non-noble
metals such as Co, Fe, and Ni, which not only greatly reduces their cost
but also can remarkably enhance their catalytic activities, as a result of
the synergistic structural and electronic effects of the two metals (via
the so-called strain and ligand effects) [9–11]. It is well-known that
iron is an abundance and magnetism material. When it is successfully
employed as the core, the obtained catalysts naturally combine the ad-
vantages of low cost and an easy recovery function derived from using
of an external magnetic field [12–15].
2. Experiment
2.1. Characterization methods
Pd content of the catalyst was measured by inductively coupled plas-
ma (ICP) on an IRIS Advantage analyzer. The size and morphology of the
magnetic nanoparticles were observed by a Hitachi-600 electron micro-
scope, with an accelerating voltage of 100 kV. XRD measurements were
performed on a Rigaku D/max-2400 diffractometer using Cu-K α radia-
tion as the X-ray source in the 2θ range of 10–90°. Magnetic measure-
ments of samples were investigated with a Quantum Design vibrating
sample magnetometer (VSM) at room temperature in an applied
It is representative that Palladium-catalyzed Suzuki and Heck cou-
pling is a fascinating reaction for the construction of C\C bonds and
plays an important role in pharmaceutical industry and organic synthesis
⁎
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