Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia
A long-chain hydrocarbon biofuel of jet fuel range can be produced via aldol condensation of fermented products such as acetone and alcohols over the catalysts containing both metallic sites for the dehydrogenation of alcohols and basic sites for the condensation reaction. However, an efficient cata...
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doaj-6893b770df4346078674bf510cf7dbb92020-11-24T23:55:15ZengMDPI AGCatalysts2073-43442017-08-017924910.3390/catal7090249catal7090249Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-ZirconiaMinseok Kim0Jongha Park1Hari Prasad Reddy Kannapu2Young-Woong Suh3Department of Chemical Engineering, Hanyang University, Seoul 04763, KoreaDepartment of Chemical Engineering, Hanyang University, Seoul 04763, KoreaDepartment of Chemical Engineering, Hanyang University, Seoul 04763, KoreaDepartment of Chemical Engineering, Hanyang University, Seoul 04763, KoreaA long-chain hydrocarbon biofuel of jet fuel range can be produced via aldol condensation of fermented products such as acetone and alcohols over the catalysts containing both metallic sites for the dehydrogenation of alcohols and basic sites for the condensation reaction. However, an efficient catalyst system has not been studied widely yet the route is promising for biofuel production. In this work, Cu catalysts supported on ceria-zirconia (Cu/xCeZr) were prepared using coprecipitated CexZr1-xO2 supports with different Ce/Zr ratios for the cross-aldol condensation of acetone and n-butanol into mono- and di-alkylated aliphatic ketones, 2-heptanone and 6-undecanone. The acetone conversion and 6-undecanone selectivity increased with specific Cu surface area due to formation of the dehydrogenation product butyraldehyde at a higher concentration. The total yield of cross-aldol condensation products was strongly dependent on a combination of Cu sites and basic sites. This was confirmed by the results in the reaction between acetone and butyraldehyde over supported Cu catalysts that additionally examined the adsorbed acyl species on Cu surface taking part in the aldol condensation reaction. The best catalytic performance was achieved with Cu/0.8CeZr showing the largest Cu surface and the highest base site density among Cu/xCeZr catalysts. While the activity of Cu/0.8CeZ was comparable to or a little higher than that of Cu/MgO, the former catalyst was more stable than the latter suffering from the transformation of MgO to Mg(OH)2 by the reaction. Consequently, it is suggested that Cu supported on ceria-zirconia of ceria rich contains such a dual function that it can efficiently catalyze the cross-aldol condensation of acetone and n-butanol.https://www.mdpi.com/2073-4344/7/9/249copperceria-zirconiadehydrogenationcross-aldol condensationbasic sites |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Minseok Kim Jongha Park Hari Prasad Reddy Kannapu Young-Woong Suh |
spellingShingle |
Minseok Kim Jongha Park Hari Prasad Reddy Kannapu Young-Woong Suh Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia Catalysts copper ceria-zirconia dehydrogenation cross-aldol condensation basic sites |
author_facet |
Minseok Kim Jongha Park Hari Prasad Reddy Kannapu Young-Woong Suh |
author_sort |
Minseok Kim |
title |
Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia |
title_short |
Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia |
title_full |
Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia |
title_fullStr |
Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia |
title_full_unstemmed |
Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia |
title_sort |
cross-aldol condensation of acetone and n-butanol into aliphatic ketones over supported cu catalysts on ceria-zirconia |
publisher |
MDPI AG |
series |
Catalysts |
issn |
2073-4344 |
publishDate |
2017-08-01 |
description |
A long-chain hydrocarbon biofuel of jet fuel range can be produced via aldol condensation of fermented products such as acetone and alcohols over the catalysts containing both metallic sites for the dehydrogenation of alcohols and basic sites for the condensation reaction. However, an efficient catalyst system has not been studied widely yet the route is promising for biofuel production. In this work, Cu catalysts supported on ceria-zirconia (Cu/xCeZr) were prepared using coprecipitated CexZr1-xO2 supports with different Ce/Zr ratios for the cross-aldol condensation of acetone and n-butanol into mono- and di-alkylated aliphatic ketones, 2-heptanone and 6-undecanone. The acetone conversion and 6-undecanone selectivity increased with specific Cu surface area due to formation of the dehydrogenation product butyraldehyde at a higher concentration. The total yield of cross-aldol condensation products was strongly dependent on a combination of Cu sites and basic sites. This was confirmed by the results in the reaction between acetone and butyraldehyde over supported Cu catalysts that additionally examined the adsorbed acyl species on Cu surface taking part in the aldol condensation reaction. The best catalytic performance was achieved with Cu/0.8CeZr showing the largest Cu surface and the highest base site density among Cu/xCeZr catalysts. While the activity of Cu/0.8CeZ was comparable to or a little higher than that of Cu/MgO, the former catalyst was more stable than the latter suffering from the transformation of MgO to Mg(OH)2 by the reaction. Consequently, it is suggested that Cu supported on ceria-zirconia of ceria rich contains such a dual function that it can efficiently catalyze the cross-aldol condensation of acetone and n-butanol. |
topic |
copper ceria-zirconia dehydrogenation cross-aldol condensation basic sites |
url |
https://www.mdpi.com/2073-4344/7/9/249 |
work_keys_str_mv |
AT minseokkim crossaldolcondensationofacetoneandnbutanolintoaliphaticketonesoversupportedcucatalystsonceriazirconia AT jonghapark crossaldolcondensationofacetoneandnbutanolintoaliphaticketonesoversupportedcucatalystsonceriazirconia AT hariprasadreddykannapu crossaldolcondensationofacetoneandnbutanolintoaliphaticketonesoversupportedcucatalystsonceriazirconia AT youngwoongsuh crossaldolcondensationofacetoneandnbutanolintoaliphaticketonesoversupportedcucatalystsonceriazirconia |
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