catalytic conversion of furfural at 1.5 MPa, 130 1C for 24 h,
and the results are shown in Fig. 2. It shows that the catalytic
performance remains almost the same at the first three cycles,
indicating the good stability of the catalyst.
In summary, we have developed a new route to produce
1
,5-pentanediol from furfural over Cop-Pt/Co AlO catalyst.
2 4
It is low cost and could be operated under mild conditions. In
particular, at 1.5 MPa, 140 1C, 1,5-pentanediol yield reaches
B35% after reaction for 24 h; this is the highest value reported
Scheme 2 Proposed catalytic mechanism for the direct conversion of
furfural to 1,5-pentanediol over Pt/Co AlO
2
4
.
under mild conditions so far. In this kind of catalysts, CoO
3
x
However, there are more by-products generated and the
stability is poorer than Cop-Pt/Co AlO
+
(
Co
ions, especially) is mainly responsible for the absorp-
2
4
.
tion of CQC and the opening of the furan ring, while Pt
works for the following hydrogenation. This rule can guide the
design of more-efficient and stable catalysts for the catalytic
direct conversion of furfural to 1,5-pentanediol with high
stability.
It can be seen from the above results that the hydrogenolysis
products (I–IV) always exist, which is related to the surface
acid–base properties of the catalyst. Many works have indicated
that the better selectivity can be obtained over Pt or Cu
catalysts loaded on basic supports in the selective hydrogena-
1
2
This project was supported financially by the 973 Program
of China (2010CB732300), the National Natural Science
Foundation of China (No. 20973058), the Commission of Science
and Technology of Shanghai Municipality (08JC1407900,
tion of furfural to furfuryl alcohol, such as Pt/ZrO
1
2
/MgO
4,15
and Cu/MgO.
This may be because the basic supports
could suppress step E partly. It is also reported that the
promotion with Li can particularly increase the density of
low-coordination oxygen anions on MgO surface and lead to
1
0XD1401400) and the ‘‘Excellent scholarship’’ of East China
1
6
University of Science and Technology, China. We thank
Prof. Yun Guo and Prof. Xueqing Gong for useful discussions.
2 4
higher basicity. So, we prepare a Li-modified Pt/Co AlO
catalyst by co-precipitation, its catalytic properties are tested
at 120–150 1C, 1.5 MPa and shown in Table 1. The yield of
products I–IV really decreases obviously in the temperature
range of 120–140 1C, but increases again at 150 1C. The iso-
merisation of 1,2-pentanediol to 1,4-pentanediol is also prevented.
The yields of products VI and VIII reach 16.2% and 34.9%,
respectively at 140 1C, but decrease again at 150 1C; the total
yield for diol reaches 51%.
Notes and references
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Fig. 2 The recyclability experiments of Li-modified Cop-Pt/Co
2 4
AlO
1
in direct conversion at 1.5 Mpa and 130 1C.
3
926 Chem. Commun., 2011, 47, 3924–3926
This journal is c The Royal Society of Chemistry 2011