Knoevenagel condensation reaction over acid–base bifunctional nanocrystalline Ce Zr1−O2 solid solutions

Postole, G.; Chowdhury, Biswajit; Karmakar, Bikash; Pinki, Kumari; Banerji, Julie; Auroux, A.

doi:10.1016/j.jcat.2009.10.022

Cited by 179 publications

(104 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Ceria-zirconia shows interesting catalytic performances in the Knoevenagel condensation between benzaldehyde and malononitrile (Scheme 20) with ethanol as a solvent at 80 8C. [231] The direct correlation between the concentration of acidic sites and the yield of the products indicated that a higher concentration of acidic sites gives more products in the reaction even if the presence of basic sites remains obligatory. Ce x Zr 1Àx O 2 catalysts can be interesting alternatives to soluble bases in view of the following advantages: (1) high catalytic activity under mild reaction conditions, (2) easy separation of the catalyst after the reaction, and (3) reusability of the catalyst.…”

Section: Knoevenagel Condensation Reactionmentioning

confidence: 99%

See 1 more Smart Citation

Ceria‐Based Solid Catalysts for Organic Chemistry

Vivier¹,

Duprez²

2010

ChemSusChem

357

244

View full text Add to dashboard Cite

Ceria has been the subject of thorough investigations, mainly because of its use as an active component of catalytic converters for the treatment of exhaust gases. However, ceria‐based catalysts have also been developed for different applications in organic chemistry. The redox and acid–base properties of ceria, either alone or in the presence of transition metals, are important parameters that allow to activate complex organic molecules and to selectively orient their transformation. Pure ceria is used in several organic reactions, such as the dehydration of alcohols, the alkylation of aromatic compounds, ketone formation, and aldolization, and in redox reactions. Ceria‐supported metal catalysts allow the hydrogenation of many unsaturated compounds. They can also be used for coupling or ring‐opening reactions. Cerium atoms can be added as dopants to catalytic system or impregnated onto zeolites and mesoporous catalyst materials to improve their performances. This Review demonstrates that the exceptional surface (and sometimes bulk) properties of ceria make cerium‐based catalysts very effective for a broad range of organic reactions.

show abstract

Section: Knoevenagel Condensation Reactionmentioning

confidence: 99%

“…Ce x Zr 1Àx O 2 catalysts can be interesting alternatives to soluble bases in view of the following advantages: (1) high catalytic activity under mild reaction conditions, (2) easy separation of the catalyst after the reaction, and (3) reusability of the catalyst. [231] …”

Section: Knoevenagel Condensation Reactionmentioning

confidence: 99%

Ceria‐Based Solid Catalysts for Organic Chemistry

Vivier¹,

Duprez²

2010

ChemSusChem

357

244

View full text Add to dashboard Cite

show abstract

“…The Ce/Zr ratio of 1:1 was found to be optimum in catalyzing both ketonization and aldol condensation reactions, resulting from the best combination of each reaction activity as well as catalyst stability. This composition of ceria-zirconia catalyst has been used in upgrading light fractions of a simulated bio-oil [11], aldehyde [12], and carboxylic acids [13,14]. A catalyst consisting of Pd metal and Ce0.5Zr0.5O2 support was also demonstrated to be stable and effective in the ketonization reaction [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia

et al. 2017

View full text Add to dashboard Cite

Abstract: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 Ce x Zr 1-x O 2 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.

show abstract

“…The band at 270 nm appears asymmetric, and the shoulder centered at 358 nm corresponds to the transitions of Cu 2+ in tetragonal oxygen configuration (Liang et al, 2012), which can be related to copper clusters dispersed on the ZSM-5 surface. Eight coordinated tetravalent zirconium species are also responsible for the absorption in the range of 200-220 nm (Postole et al, 2010). The band at 550-1000 nm corresponds to the CuO phase, due to the Cu 2+ transition in octahedral oxygen configuration (Praliaud et al, 1998).…”

Section: Resultsmentioning

confidence: 99%

Influence of Ce/Zr Ratio on the Synergistic Effect over CuCe_1–xZr_xO_y/ZSM-5 Catalysts for the Self-Sustained Combustion of Carbon Monoxide

Zhao

Hao

Bin

et al. 2017

Combustion Science and Technology

View full text Add to dashboard Cite

The self-sustained combustion of CO was studied over a series of CuCe 1-x Zr x O y /ZSM-5 catalysts with different Ce/Zr molar ratios to evaluate the correlation of their structural characteristics with catalytic performance. The obtained results demonstrated that the activity of the cerium-containing catalysts was much higher than that of the CuZr 1 /Z, with the activity of CO combustion following the order: CuZr 1 /Z < CuCe 0.25 Zr 0.75 /Z < CuCe 0.5 Zr 0.5 /Z < CuCe 1 /Z < CuCe 0.75 Zr 0.25 Z. After cerium addition, the cerium-zirconium mixed oxides formed promoted the copper species well dispersed on the catalyst surface. The high activities of cerium-containing catalysts were closely related to the synergetic effects among the copper, cerium, and zirconium species, as the surface copper species provided sites for CO adsorption and the cerium-zirconium mixed oxides promote the activation of oxygen. The activities were probably also attributed to some copper species present as substitutional defects in the ceria lattice, which were more reducible than the copper clusters, minicrystals, and bulk CuO particles. The CuCe 0.75 Zr 0.25 /Z possessed excellent redox capacity, adsorption/activation properties for O and CO species, and therefore induced a self-sustained combustion of CO at the lowest temperature than that of other CuCe 1-x Zr x O y /ZSM-5 catalysts.ARTICLE HISTORY

show abstract

Knoevenagel condensation reaction over acid–base bifunctional nanocrystalline Ce Zr1−O2 solid solutions

Cited by 179 publications

References 52 publications

Ceria‐Based Solid Catalysts for Organic Chemistry

Ceria‐Based Solid Catalysts for Organic Chemistry

Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia

Influence of Ce/Zr Ratio on the Synergistic Effect over CuCe_1–xZr_xO_y/ZSM-5 Catalysts for the Self-Sustained Combustion of Carbon Monoxide

Contact Info

Product

Resources

About

Knoevenagel condensation reaction over acid–base bifunctional nanocrystalline Ce Zr1−O2 solid solutions

Cited by 179 publications

References 52 publications

Ceria‐Based Solid Catalysts for Organic Chemistry

Ceria‐Based Solid Catalysts for Organic Chemistry

Cross-Aldol Condensation of Acetone and n-Butanol into Aliphatic Ketones over Supported Cu Catalysts on Ceria-Zirconia

Influence of Ce/Zr Ratio on the Synergistic Effect over CuCe1–xZrxOy/ZSM-5 Catalysts for the Self-Sustained Combustion of Carbon Monoxide

Contact Info

Product

Resources

About

Influence of Ce/Zr Ratio on the Synergistic Effect over CuCe_1–xZr_xO_y/ZSM-5 Catalysts for the Self-Sustained Combustion of Carbon Monoxide