Abstract
Carbon-supported AuPd bimetallic nanoparticles were synthesized, characterized, and evaluated as catalysts in the aqueous-phase selective oxidation of glycerol. The bimetallic catalysts were synthesized by two different methods. The first method involved the deposition of Au onto the surface of 3-nm supported Pd particles by catalytic reduction of HAuCl4 in aqueous solution by H2. The second method used the formation of a AuPd sol that was subsequently deposited onto a carbon support. Characterization of the catalysts using analytical transmission electron microscopy, H2 titration, and X-ray absorption spectroscopy at the Au LIII and Pd K-edges confirmed that the first synthesis method successfully deposited Au onto the Pd particles. Results from the AuPd sol catalyst also revealed that Au was preferentially located on the surface. Measurement of glycerol oxidation rates (0.3 M glycerol, 0.6 M NaOH, 10 atm O2, 333 K) in a semibatch reactor gave a turnover frequency (TOF) of 17 s-1 for monometallic Au and 1 s-1 for monometallic Pd, with Pd exhibiting a higher selectivity to glyceric acid. Although the activity of the bimetallic AuPd catalysts depended on the amount of Au present, none of them had a TOF greater than that of the monometallic Au catalyst. However, the AuPd catalysts had higher selectivity to glyceric acid compared with the monometallic Au. Because a physical mixture of monometallic Au and Pd catalysts also gave higher selectivity to glyceric acid, the Pd is proposed to catalyze the decomposition of the side product H2O2 that is also formed over the Au but is detrimental to the selectivity toward glyceric acid.
| Original language | English |
|---|---|
| Pages (from-to) | 264-273 |
| Number of pages | 10 |
| Journal | Journal of Catalysis |
| Volume | 250 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Sep 10 2007 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Catalysis
- Physical and Theoretical Chemistry
Cite this
Selective oxidation of glycerol over carbon-supported AuPd catalysts. / Ketchie, William C.; Murayama, Mitsuhiro; Davis, Robert J.
In: Journal of Catalysis, Vol. 250, No. 2, 10.09.2007, p. 264-273.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Selective oxidation of glycerol over carbon-supported AuPd catalysts
AU - Ketchie, William C.
AU - Murayama, Mitsuhiro
AU - Davis, Robert J.
PY - 2007/9/10
Y1 - 2007/9/10
N2 - Carbon-supported AuPd bimetallic nanoparticles were synthesized, characterized, and evaluated as catalysts in the aqueous-phase selective oxidation of glycerol. The bimetallic catalysts were synthesized by two different methods. The first method involved the deposition of Au onto the surface of 3-nm supported Pd particles by catalytic reduction of HAuCl4 in aqueous solution by H2. The second method used the formation of a AuPd sol that was subsequently deposited onto a carbon support. Characterization of the catalysts using analytical transmission electron microscopy, H2 titration, and X-ray absorption spectroscopy at the Au LIII and Pd K-edges confirmed that the first synthesis method successfully deposited Au onto the Pd particles. Results from the AuPd sol catalyst also revealed that Au was preferentially located on the surface. Measurement of glycerol oxidation rates (0.3 M glycerol, 0.6 M NaOH, 10 atm O2, 333 K) in a semibatch reactor gave a turnover frequency (TOF) of 17 s-1 for monometallic Au and 1 s-1 for monometallic Pd, with Pd exhibiting a higher selectivity to glyceric acid. Although the activity of the bimetallic AuPd catalysts depended on the amount of Au present, none of them had a TOF greater than that of the monometallic Au catalyst. However, the AuPd catalysts had higher selectivity to glyceric acid compared with the monometallic Au. Because a physical mixture of monometallic Au and Pd catalysts also gave higher selectivity to glyceric acid, the Pd is proposed to catalyze the decomposition of the side product H2O2 that is also formed over the Au but is detrimental to the selectivity toward glyceric acid.
AB - Carbon-supported AuPd bimetallic nanoparticles were synthesized, characterized, and evaluated as catalysts in the aqueous-phase selective oxidation of glycerol. The bimetallic catalysts were synthesized by two different methods. The first method involved the deposition of Au onto the surface of 3-nm supported Pd particles by catalytic reduction of HAuCl4 in aqueous solution by H2. The second method used the formation of a AuPd sol that was subsequently deposited onto a carbon support. Characterization of the catalysts using analytical transmission electron microscopy, H2 titration, and X-ray absorption spectroscopy at the Au LIII and Pd K-edges confirmed that the first synthesis method successfully deposited Au onto the Pd particles. Results from the AuPd sol catalyst also revealed that Au was preferentially located on the surface. Measurement of glycerol oxidation rates (0.3 M glycerol, 0.6 M NaOH, 10 atm O2, 333 K) in a semibatch reactor gave a turnover frequency (TOF) of 17 s-1 for monometallic Au and 1 s-1 for monometallic Pd, with Pd exhibiting a higher selectivity to glyceric acid. Although the activity of the bimetallic AuPd catalysts depended on the amount of Au present, none of them had a TOF greater than that of the monometallic Au catalyst. However, the AuPd catalysts had higher selectivity to glyceric acid compared with the monometallic Au. Because a physical mixture of monometallic Au and Pd catalysts also gave higher selectivity to glyceric acid, the Pd is proposed to catalyze the decomposition of the side product H2O2 that is also formed over the Au but is detrimental to the selectivity toward glyceric acid.
UR - http://www.scopus.com/inward/record.url?scp=34547805554&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34547805554&partnerID=8YFLogxK
U2 - 10.1016/j.jcat.2007.06.011
DO - 10.1016/j.jcat.2007.06.011
M3 - Article
AN - SCOPUS:34547805554
VL - 250
SP - 264
EP - 273
JO - Journal of Catalysis
JF - Journal of Catalysis
SN - 0021-9517
IS - 2
ER -