Y. Yu et al. / Journal of Molecular Catalysis A: Chemical 337 (2011) 77–81
81
Table 6
The catalytic performance of the regenerated and the fresh C1 1 2 catalysts.a
Reaction time (h)
MA conversion (%)
Selectivity (%)
Fresh (F)
Regenerated (R)
GBL
THF
SA
F
R
F
R
F
R
1
2
3
4
100.0
100.0
99.6
100.0
100.0
99.0
100.0
100.0
99.3
100.0
100.0
98.6
–
–
0.3
0.2
–
–
0.1
-
–
–
0.4
2.8
–
–
1.3
3.3
94.1
94.3
97.0
96.7
a
Reaction conditions: 6 mL catalyst, 0.1 MPa, 240 ◦C, 30 mL min−1 H2, and 0.6 h−1 LHSV of MA in GBL.
catalyst for the gas-phase hydrogenation of MA to GBL at atmo-
spheric pressure were investigated. C1 1 2 catalyst shows better
catalytic performance, in which the conversion of MA and the selec-
tivity of GBL were both 100% within two hours under the reaction
conditions of 6 mL catalyst, 220–280 ◦C, 30 mL min−1 H2, 0.6 h−1
LHSV of MA in GBL. Lower LHSV of raw material is beneficial to
increase the catalytic performance and the stability of C1 1 2 catalyst.
Smaller crystallite size of Cu and higher metallic Cu surface area are
favorable to increase the catalytic performance of Cu–CeO2–Al2O3
catalyst. The deactivation of Cu–CeO2–Al2O3 catalyst is due to for-
mation of the compact wax-like surface deposition of the catalyst,
which is probably ascribed to the strong adsorption of SA and then
polymerization on the surfaceofcatalyst. Thecatalytic performance
of the regenerated catalyst can be recovered completely by the
regeneration method of N2–air–H2 stage treatment.
Acknowledgments
Fig. 4. TG-DTA profiles of the used C1 1 2 catalyst.
This project was supported financially by National Basic
Research Program of China (2010CB732300) and Program for New
Century Excellent Talents in University (NCET-09-0343).
Cu–CeO2–Al2O3 catalyst started to deactivate after reaction for sev-
eral hours, both the conversion of MA and the selectivity of GBL
not be hydrogenated to GBL promptly and was adsorbed strongly
then polymerized on the catalyst surface, which resulted in the fast
deactivation of catalyst.
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Effects of catalyst composition, reaction temperature, and LHSV
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