Catalysis Science & Technology
Communication
spectra of pure SiC and Pd/SiC under the 320 nm excitation
wavelength at room temperature. The PL peaks of both sam-
ples range from 400 to 550 nm, which are consistent with the
stability for the photocatalytic hydrogenation of furan and its
derivatives.
2
1
literature. The PL intensity of Pd/SiC has an obvious decre-
ment comparing with that of pure SiC, indicating that the
recombination of the photogenerated electrons and holes has
been effectively suppressed. This further confirms the trans-
fer of electrons from SiC to the Pd particles. The electron
transfer results in a positively charged region in SiC and a
Conclusions
The present work suggests a new class of photocatalysts,
photo-active-semiconductor supported metal nanoparticles,
which can make some chemical reactions performing usually
at high temperature and pressure occur under moderate light
irradiation. SiC-supported Pd nanoparticles can greatly pro-
mote the hydrogenation of furan derivatives at a lower tem-
1
9
negatively charged Pd nanoparticle. The light irradiation
can effectively amplify the directed electron transfer. There-
fore, the photogenerated electrons can quickly transfer from
perature (25 °C) and pressure (1 Mpa of H
irradiation. The yield of tetrahydrofuran from furan hydroge-
2
) by visible light
2
2
SiC to Pd and thus avoid recombination with the holes.
Furan molecules usually adsorb with its molecular plane
lying parallel to the surface of the Pd particles, and its C–C
and CC bonds are located respectively on the top of a Pd
−
1
nation is 99% and the turnover frequency is 70 h . The
heterojunction between SiC and Pd can facilitate the quick
transfer of the photogenerated electrons from SiC to Pd.
These energetic electrons on the surface of the Pd nano-
particles significantly enhance their intrinsic catalytic activity.
The novel processes using the Pd/SiC photocatalyst have the
potential to utilize solar energy and are greener than conven-
tional catalytic processes driven by heating.
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3
atom. So, the negatively charged Pd nanoparticles with
more energetic electrons activate the CC bonds in the
furan rings by donating electrons back to the CC anti-
bonds. Kamat's group studied the photocatalytic perfor-
mances of the Au–TiO
suggested that the photogenerated electrons can transfer
from TiO to the metal nanoparticles and the holes left on
TiO are scavenged by ethanol.
2 2
and Ag@TiO composites and
2
2
4,25
2
In our case, the holes left
Acknowledgements
on the SiC support are filled by oxidizing H , which generates
2
active hydrogen. The active hydrogen then migrates to the Pd
This work was financially supported by in-house research
projects of SKLCC (2013BWZ006 and 2014BWZ006).
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6
nanoparticles by reverse spillover and reacts with the CC
bonds in furan to produce THF. When the furan rings have
substituent groups, the steric effect of the substituent groups
can decrease the hydrogenation activity of the CC bonds in
the furan rings but promote the hydrogenolysis of the furan
rings. As a result, both the activity and selectivity for the
hydrogenation of furan derivatives slightly decrease, as
shown in Table 1.
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Fig. 5 The photocatalytic stability of 3 wt% Pd/SiC in 5 rounds.
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