Abstract
Aromatic azo compounds are high-value chemicals extensively used as pigments, drugs, and food additives, but their production typically requires stoichiometric amounts of environmentally unfriendly metals or nitrites. There is an urgent need to develop a dual catalytic system capable of reducing nitroaromatics to aromatic amines, followed by their oxidation to azo compounds. Here we report such a dual catalyst based on Ag@Pd-Ag core-frame nanocubes for the stepwise conversion of 4-nitrothiophenol to trans-4,4′-dimercaptoazobenzene under ambient conditions. Our in situ surface-enhanced Raman spectroscopy study reveals three sequential processes that include the Pd-catalyzed reduction of 4-nitrothiophenol to 4-aminothiophenol by hydrogen, a period during which the 4-aminothiophenol remain unchanged until all hydrogen has depleted, and the Ag-catalyzed oxidation of 4-aminothiophenol to trans-4,4′-dimercaptoazobenzene by the O2 from air. This work will lead to an environmentally friendly and sustainable approach to the production of aromatic azo compounds.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 786-790 |
| Number of pages | 5 |
| Journal | ChemNanoMat |
| Volume | 2 |
| Issue number | 8 |
| DOIs | |
| State | Published - Jan 1 2016 |
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Keywords
- Ag-catalyzed oxidation
- bimetallic nanocrystals
- catalysis
- Pd-catalyzed reduction
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Renewable Energy, Sustainability and the Environment
- Biomaterials
- Materials Chemistry
Cite this
A Dual Catalyst with SERS Activity for Probing Stepwise Reduction and Oxidation Reactions. / Li, Jumei; Wu, Yiren; Sun, Xiaojun; Liu, Jingyue; Winget, Sarah A.; Qin, Dong.
In: ChemNanoMat, Vol. 2, No. 8, 01.01.2016, p. 786-790.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A Dual Catalyst with SERS Activity for Probing Stepwise Reduction and Oxidation Reactions
AU - Li, Jumei
AU - Wu, Yiren
AU - Sun, Xiaojun
AU - Liu, Jingyue
AU - Winget, Sarah A.
AU - Qin, Dong
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Aromatic azo compounds are high-value chemicals extensively used as pigments, drugs, and food additives, but their production typically requires stoichiometric amounts of environmentally unfriendly metals or nitrites. There is an urgent need to develop a dual catalytic system capable of reducing nitroaromatics to aromatic amines, followed by their oxidation to azo compounds. Here we report such a dual catalyst based on Ag@Pd-Ag core-frame nanocubes for the stepwise conversion of 4-nitrothiophenol to trans-4,4′-dimercaptoazobenzene under ambient conditions. Our in situ surface-enhanced Raman spectroscopy study reveals three sequential processes that include the Pd-catalyzed reduction of 4-nitrothiophenol to 4-aminothiophenol by hydrogen, a period during which the 4-aminothiophenol remain unchanged until all hydrogen has depleted, and the Ag-catalyzed oxidation of 4-aminothiophenol to trans-4,4′-dimercaptoazobenzene by the O2 from air. This work will lead to an environmentally friendly and sustainable approach to the production of aromatic azo compounds.
AB - Aromatic azo compounds are high-value chemicals extensively used as pigments, drugs, and food additives, but their production typically requires stoichiometric amounts of environmentally unfriendly metals or nitrites. There is an urgent need to develop a dual catalytic system capable of reducing nitroaromatics to aromatic amines, followed by their oxidation to azo compounds. Here we report such a dual catalyst based on Ag@Pd-Ag core-frame nanocubes for the stepwise conversion of 4-nitrothiophenol to trans-4,4′-dimercaptoazobenzene under ambient conditions. Our in situ surface-enhanced Raman spectroscopy study reveals three sequential processes that include the Pd-catalyzed reduction of 4-nitrothiophenol to 4-aminothiophenol by hydrogen, a period during which the 4-aminothiophenol remain unchanged until all hydrogen has depleted, and the Ag-catalyzed oxidation of 4-aminothiophenol to trans-4,4′-dimercaptoazobenzene by the O2 from air. This work will lead to an environmentally friendly and sustainable approach to the production of aromatic azo compounds.
KW - Ag-catalyzed oxidation
KW - bimetallic nanocrystals
KW - catalysis
KW - Pd-catalyzed reduction
UR - http://www.scopus.com/inward/record.url?scp=84992200717&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84992200717&partnerID=8YFLogxK
U2 - 10.1002/cnma.201600153
DO - 10.1002/cnma.201600153
M3 - Article
AN - SCOPUS:84992200717
VL - 2
SP - 786
EP - 790
JO - ChemNanoMat
JF - ChemNanoMat
SN - 2199-692X
IS - 8
ER -