DOI: 10.1002/cctc.201500242
Full Papers
An Investigation of the Effect of the Addition of Tin to
%Pd/TiO for the Hydrogenation of Furfuryl Alcohol
5
2
Gavin M. King, Sarwat Iqbal, Peter J. Miedziak, Gemma L. Brett, Simon A. Kondrat,
Benjamin R. Yeo, Xi Liu, Jennifer K. Edwards, David J. Morgan, David K. Knight, and
[a]
Graham J. Hutchings*
The selective hydrogenation of furfuryl alcohol was investigat-
ed at room temperature by using supported palladium cata-
lysts. The catalysts are very selective to the formation of 2-
methylfuran. Furthermore, the addition of tin to palladium
showed similar catalytic activity, but was more selective to tet-
rahydrofurfuryl alcohol. Variation of the Sn/Pd ratio has shown
a considerable and interesting effect on the selectivity pattern.
Addition of a small amount of Sn (1 wt%) shifted the selectivi-
ty towards tetrahydrofurfuryl alcohol and methyltetrahydrofur-
an, which are ring-saturated molecules. Increasing the tin ratio
further decreased the catalytic activity and also showed very
poor selectivity to either of these products.
Introduction
Furfuryl alcohol (FA) is an important bioderivative obtained
from the hydrogenation of furfural, a product of xylose conver-
phase. Pd-, Rh- and Pt-supported catalysts are observed to be
less active compared with nickel, even at higher temperatures
[
1]
[7b, 8]
sion. Selective hydrogenation and hydrogenolysis are consid-
ered to be the most effective methods for the conversion of
furan compounds to valuable chemicals. There are studies that
report the conversion of furfuryl alcohol into various fuel com-
and pressures.
All of these reports have shown the require-
ment for very harsh reaction conditions, both in terms of tem-
perature and hydrogen pressure. Therefore, a process for the
selective synthesis of 2-MF under green reaction conditions is
desirable, but challenging, owing to the formation of various
byproducts. We have recently reported that a 5 wt% Pd/TiO2
catalyst can be used very effectively for the conversion of fur-
furyl alcohol into 2-methylfuran in 1,2-dichloroethane solvent
[2]
ponents, for example, 1,5-pentanediols, tetrahydrofurfuryl al-
[
3]
[4]
cohol (THFA), and 2-methylfuran (2-MF). All of these compo-
nents are important in terms of their application, but their syn-
thesis under green reaction conditions represents a significant
[
5]
[9]
challenge. 2-MF is obtained from the hydrogenation of FA
and furfural and is mainly used for the synthesis of crysanthe-
mate pesticides, perfume intermediates and chloroquine lateral
at room temperature. Herein, we have compared the catalytic
[
9]
activity of the previously reported 5 wt% Pd/TiO2 catalyst
with a commercially available 5 wt% Pd/TiO catalyst that can
2
[6]
chains in medical applications. In 1931 copper chromite was
the first catalyst reported for the conversion of FA in the liquid
be used to benchmark our preparation method. Interestingly,
there are differences in both the catalytic activity and the se-
lectivity pattern for these two catalysts. These differences
appear to be linked to the oxidation state of Pd in both cata-
lysts. Furthermore, we have studied the addition of a second
component, namely Sn, and observed similar catalytic activity,
but more effective hydrogenation, with respect to double-
bond saturation in the ring, which differs from the unmodified
[
2]
phase at 1008C and 100–150 bar pressure of hydrogen.
A
yield of 70% pentanediol was observed under these reaction
conditions. Subsequently, the synthesis of 2-MF was reported
[5a]
using Cr-based catalysts. Nickel has been reported to be a se-
lective catalyst for the synthesis of tetrahydrofurfuryl alcohol
(
THFA) from FA under very harsh reaction conditions (1808C,
[
5c, 7]
[4]
[6a]
3
.5 h).
Ni and Cu
catalysts have been stated to be
Pd/TiO catalyst. In addition, we have also studied the effect of
2
active catalysts for the selective hydrogenation of FA to 2-MF
solvents, for example, methanol and ethanol, methanol was
found to be a suitable alternative for 1,2-dichloroethane. The
reaction was found to be less selective to 2-MF and a second
product, THFA, was obtained when a Pd/Sn catalyst in 1:1 ratio
was used. THFA is a low cost, biodegradable solvent with
many agricultural and industrial applications. It can be pre-
pared by the hydrogenation of furfural over Ni and CuÀCr cat-
[
5c]
and furan. Pt, Pd and Ru catalysts supported on MnO have
been reported to be very efficient materials for the hydrogena-
tion of FA at 1208C, 30–60 bar H , for 4 h in the aqueous
2
[
a] G. M. King, Dr. S. Iqbal, Dr. P. J. Miedziak, Dr. G. L. Brett, Dr. S. A. Kondrat,
B. R. Yeo, Dr. X. Liu, Dr. J. K. Edwards, Dr. D. J. Morgan, Prof. D. K. Knight,
Prof. G. J. Hutchings
[
2,3]
alyst,
however, severe environmental pollution can be creat-
Cardiff Catalysis Institute
Main Building Park Place, Cardiff, CF10 3AT (UK)
E-mail: hutch@cardiff.ac.uk
ed during the preparation and recycling of the CuÀCr catalyst
[5b]
system and a large amount of furfural condensates can be
formed in this process. Ni, Pd, Ru and Rh, catalysts are com-
monly employed for the synthesis of THFA from furfuryl alco-
hol at temperatures above 508C using long reaction
This publication is part of a Special Issue on Palladium Catalysis. To view
ChemCatChem 2015, 7, 2122 – 2129
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