DOI: 10.1002/cctc.201802044
Full Papers
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Mild Hydrogenation of α-Pinene Catalyzed by Ru
Nanoparticles Loaded on Boron-doped Amphiphilic
Core-Shell Mesoporous Molecular Sieves
[a]
[a]
[a]
[a]
[a]
[a]
[a]
Fengli Yu, Lihua Xie, Fangzhu Wu, Bing Yuan, Congxia Xie,* Shitao Yu,* Xien Liu,
[a]
[b]
Lei Wang, and Dan Wang
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Highly dispersed and stable catalysts comprising Ru nano-
particles supported on boron-doped amphiphilic core-shell
Ru nanoparticles, and to simplify their dispersion in the water-
organic reaction medium. Moreover, B-doped molecular sieves
may adjust their acidity to meet the needs of α-pinene
mesoporous molecular sieves (MMSÀ C@MMSÀ NH /B/Ru) with
2
alkyl-modified hydrophobic silica core and NH -functionalized
hydrogenation. Under mild reaction conditions (25°C, 1 MPa H ,
2
2
hydrophilic silica shell are successfully prepared for use in
hydrogenation of α-pinene for the first time. Dodecyl-modified
MMSÀ C @MMSÀ NH /B/Ru exhibits the best catalytic activity
and 1 h), α-pinene can be completely converted with 99%
selectivity to cis-pinane, because every nanocomposite is
equivalent to a microreactor. The catalytic activity does not
change much over 5 cycles, indicating that Ru nanoparticles are
stably loaded on the molecular sieves.
12
2
under mild hydrogenation conditions. The abundant À NH
2
functional groups on the molecular sieve surface and their
amphipathy allow the sieves to facilitate attachment of more
[
6]
Introduction
Raney-Ni and Pd/C. However, the catalytic activity decayed
quickly owing to the aggregation of the nanoparticles. To prevent
the aggregation of metal nanoparticles, some stabilizers, such as
nonionic surfactants and polymers are usually added to the
Biomass utilization has been attracting increased attention
because it can ensure energy security, protect the environment,
and promote sustainable development of the eco-society.
Turpentine obtained from pine trees is one of the naturally rich
resources that contains more than 80% of α-pinene. Pinane,
obtained by the hydrogenation of α-pinene, is an important
chemical intermediate for the synthesis of valuable spices,
medicines, and other fine chemicals. Two species, including cis-
pinane and trans-pinane, can be obtained during the hydro-
genation of α-pinene, but cis-pinane exhibits higher reactivity
[1]
[7]
catalytic system. Our research group has also made progress in
the stabilization of metal nanoparticles with the use of some
polymers, such as PVA, F127, P123, and TPGS-1000. However, the
addition of stabilizers may lead to the formation of emulsions,
thus resulting in difficulties in product separation. Currently, the
developed alternative approach is to ensure the attachment of
nanoparticles on solid support materials, including amorphous
silica, activated carbon, and molecular sieves. These materials play
a significant role since they prevent the aggregation of metal
[2]
[8]
[
9]
[3]
[4]
relative to trans-pinane. Therefore, it is essential to obtain a high
yield of cis-pinane during the hydrogenation of α-pinene
processes.
[10]
nanoparticles.
Among the developed supporting materials,
mesoporous molecular sieves (MMSs) have become a research
hotspot in catalysis, because their high-specific surface area could
allow the attachment of additional metal nanoparticles, while the
large, uniform pore structure, can achieve molecular shape-
Metal nanoparticles possess an excellent catalytic activity for
the hydrogenation reaction owing to their quantum sizes and
[5]
surface effects. For example, Ni nanoparticles exhibited an
[11]
excellent selectivity for cis-pinane which was better than those of
selective catalysis.
However, pure silica MMS cannot be adequately dispersed in
the organic phase owing to its inherent hydrophilicity. This
drawback can be resolved via the surface modification or
functionalization of MMS through the binding of the organic
[a] Dr. F. Yu, L. Xie, F. Wu, B. Yuan, Prof. C. Xie, Prof. S. Yu, Prof. X. Liu,
Prof. L. Wang
State Key Laboratory Base of Eco-Chemical Engineering
Taishan Scholar Advantage and Characteristic Discipline Team of Eco-Che-
mical Process and Technology
Qingdao University of Science and Technology
Qingdao, Shandong 266042 (P. R. China)
E-mail: xiecongxia@126.com
[12]
functional groups with the massive SiÀ OH on its surface. A more
important strategy is the doping of heteroatoms in molecular
[13]
sieves to improve their acidities or oxidizabilities.
MMSs, owing to their specific hydrophilic/hydrophobic properties,
acidity, or oxidizability, have been extensively used in the
Modified
b] Prof. D. Wang
[
[14]
State Key Laboratory of Biochemical Engineering
Institute of Process Engineering
Chinese Academy of Sciences
Beijing, 100190 (P. R. China)
adsorption-separation, catalysis, drug delivery, and sensors.
To-this-date, no prior report has investigated metal nano-
particles which have been loaded on an amphiphilic and doped
periodic mesoporous molecular sieve (PMMS) with a core-shell
structure. The present work first reports the synthesis of ruthenium
ChemCatChem 2019, 11, 1–9
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