Hong et al.
Hydrogenation of Succinic Acid
Table II. Catalytic performance of Re/XCu-MC catalysts in the liquid-
phase hydrogenation of succinic acid (reaction temperature = 200 ꢀC,
reaction pressure = 80 bar, reaction time = 20 h).
In order to investigate the effect of hydrogen consump-
tion by copper in the Re/XCu-MC (X = 8ꢁ0, 12.7, 15.9,
23.3, and 26.8) catalysts on the catalytic activity in the
hydrogenation of SA, a correlation between the amount of
hydrogen consumption by copper in the Re/XCu-MC cat-
alysts and yield for BDO was established. Figure 6 shows
the correlation between the amount of hydrogen consump-
tion by copper and yield for BDO in the hydrogenation
of SA. The correlation clearly shows that yield for BDO
increased with increasing the amount of hydrogen con-
sumption by copper. This result strongly supports that the
capacity of hydrogen consumption by copper served as a
key factor determining the catalytic activity in the hydro-
genation of SA to BDO over Re/XCu-MC catalysts.
Yield (%)
Conversion of SA (%)
BDO
DMS
GBL
Re/8.0Cu-MC
Re/12.7Cu-MC
Re/15.9Cu-MC
Re/23.3Cu-MC
Re/26.8Cu-MC
100
100
100
100
100
6ꢁ2
7ꢁ7
11ꢁ3
5ꢁ7
83.6
79.8
65.4
86.3
91.1
10ꢁ2
12ꢁ5
23ꢁ3
8ꢁ0
4ꢁ2
4ꢁ6
an intermediate via methylation of SA with methanol.
Cyclization of SA and DMS by rhenium component of
the catalysts produced ꢂ-butyrolactone (GBL) as a by-
product as shown in Figure 1. All the catalysts exhib-
ited a complete conversion (100%) of SA. This means
that the catalytic function of rhenium was sufficient
in the liquid-phase hydrogenation of SA to DMS over
Re/XCu-MC catalysts. However, yield for BDO showed
a volcano-shaped trend with respect to copper content.
This means that an optimal copper content was required
for maximum catalytic performance. Among the catalyst
tested, Re/15.9Cu-MC catalyst showed the highest yield
for BDO (11.3%). The enhanced catalytic performance
of Re/15.9Cu-MC might be due to the largest amount of
hydrogen consumption by copper. It has been reported that
4. CONCLUSIONS
Copper-containing mesoporous carbons (XCu-MC) with
different copper content (X = 8ꢁ0, 12.7, 15.9, 23.3, and
26.8 wt%) were prepared by a single-step surfactant-
templating method. Rhenium nano-catalysts supported on
copper-containing mesoporous carbons (Re/XCu-MC, X =
8ꢁ0, 12.7, 15.9, 23.3, and 26.8) were then prepared by an
incipient wetness method. Physicochemical properties of
Re/XCu-MC (X = 8ꢁ0, 12.7, 15.9, 23.3, and 26.8 wt%)
were affected by copper content. The amount of hydro-
gen consumption by copper in the Re/XCu-MC (X = 8ꢁ0,
Delivered by Ingenta to: Nanyang Technological University
12.7, 15.9, 23.3, and 26.8) showed a volcano-shaped trend
hydrogen consumption by metal for reduction plays an
IP: 185.14.192.15 On: Sat, 11 Jun 2016 10:52:07
with respect to copper content. In the liquid-phase hydro-
genation of SA to BDO, yield for BDO also showed a
volcano-shaped trend with respect to copper content. Yield
for BDO increased with increasing the amount of hydro-
gen consumption by copper in the Re/XCu-MC catalysts.
It is concluded that an optimal copper content was required
to achieve maximum catalytic performance of Re/XCu-
MC catalysts in the hydrogenation of SA to BDO.
Copyright: American Scientific Publishers
important role in determining the catalytic performance in
the liquid-phase hydrogenation of succinic acid.18 It has
also been reported that dealkylation of alkyl oxalate is a
rate-determining step in the hydrogenation of dicarboxylic
acid with alcohol.19 Therefore, it is believed that the excel-
lent catalytic performance of Re/15.9Cu-MC catalyst was
due to the largest amount of hydrogen consumption by
copper and the enhanced demethylation activity of copper
from DMS to BDO.
Acknowledgments: This subject is supported by Korea
Ministry of Environment as “Converging Technology
Project (202-091-001).”
12
Re/15.9Cu-MC
10
8
References and Notes
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Re/8.0Cu-MC
Re/12.7Cu-MC
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6
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A-Gen. 367, 122 (2009).
Re/23.3Cu-MC
4
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Re/26.8Cu-MC
2
0
5
10
15
20
25
Amount of hydrogen consumption by copper
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Figure 6. A correlation between the amount of hydrogen consumption
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