scholarly journals Liquid Phase Furfural Oxidation under Uncontrolled pH in Batch and Flow Conditions: The Role of In Situ Formed Base

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 73 ◽  
Author(s):  
Alessandra Roselli ◽  
Yuri Carvalho ◽  
Franck Dumeignil ◽  
Fabrizio Cavani ◽  
Sébastien Paul ◽  
...  
Keyword(s):  
Reaction Medium ◽  
Pure Oxygen ◽  
Continuous Stirred Tank Reactor ◽  
Flow Conditions ◽  
Furoic Acid ◽  
Continuous Stirred Tank ◽  
Supported Gold Nanoparticles ◽  
Supported Gold

Selective oxidation of furfural to furoic acid was performed with pure oxygen in aqueous phase under mild conditions and uncontrolled pH using hydrotalcite-supported gold nanoparticles as catalyst. Hydrotalcites with different Mg: Al ratios were tested as support. The effects of reaction time, temperature and furfural/catalyst ratio were evaluated. The catalyst Au/HT 4:1 showed the highest activity and selectivity to the desired product, achieving a complete conversion of furfural to furoic acid after 2 h at 110 °C. Further, stability tests were carried out in a continuous stirred-tank reactor and a progressive deactivation of the catalyst due to the leaching of Mg2+ cations from the support inducing changes in the pH of the reaction medium was observed.

Adherence of platelets to in situ albumin-binding surfaces under flow conditions: role of surface-adsorbed albumin

2012 ◽  
Vol 7 (4) ◽  
pp. 045007 ◽  
Author(s):  
Sanjukta Guha Thakurta ◽  
Robert Miller ◽  
Anuradha Subramanian
Keyword(s):  
Albumin Binding ◽  
Flow Conditions

Role of Hydroxyl Groups in Low-Temperature CO Catalytic Oxidation over Zn4Si2O7(OH)2 Nanowire-Supported Gold Nanoparticles

2018 ◽  
Vol 122 (44) ◽  
pp. 25456-25466 ◽  
Author(s):  
Jing-Jing Li ◽  
Bao-Lin Zhu ◽  
Gui-Chang Wang ◽  
Zun-Feng Liu ◽  
Wei-Ping Huang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Low Temperature ◽  
Catalytic Oxidation ◽  
Hydroxyl Groups ◽  
Co Catalytic Oxidation ◽  
Supported Gold Nanoparticles ◽  
Supported Gold

scholarly journals New Insights on the Dynamic Role of the Protecting Agent on the Reactivity of Supported Gold Nanoparticles

ChemCatChem ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1653-1663
Author(s):  
Giorgio Grillo ◽  
Federica Menegazzo ◽  
Silvia Tabasso ◽  
Michela Signoretto ◽  
Maela Manzoli ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Supported Gold Nanoparticles ◽  
Supported Gold

scholarly journals Versatility of Supported Gold Nanoparticles on Hydrotalcites used for Oxidation and Reduction Reactions

2021 ◽  
Vol 2 (1) ◽  
pp. 1-1
Author(s):  
Fabien Drault ◽  
◽  
Youssef Snoussi ◽  
Camila P. Ferraz ◽  
Joelle Thuriot-Roukos ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Direct Reduction ◽  
Chemical Transformations ◽  
Oxidation Reactions ◽  
Acid Base ◽  
Furoic Acid ◽  
Phase Oxidation ◽  
Supported Gold Nanoparticles ◽  
Aqueous Conditions ◽  
Supported Gold

Regardless of their size, supported gold nanoparticles are largely used for liquid-phase oxidation reactions. Small gold nanoparticles exhibit good performance during the reduction of organic compounds. The direct reduction of carboxylic acid to aldehyde is a famous and familiar reaction in the field of organic chemistry and is considered as one of the fundamental chemical transformations. Herein, we present Au/hydrotalcite, Au/MgO, and Au/Al2O3 systems as heterogeneous versatile catalysts to realize the oxidation of furfural (FF) to furoic acid (FA) and realize the reduction of FA to FF. Experiments showed that in standard aqueous conditions under air, FF can be easily oxidized to FA. When DMSO was used as a solvent to conduct the experiments under an atmosphere of CO2, FA was reduced to FF. The Au/HT series of catalysts was found to be active in both transformations, pointing out the versatility of the gold-based catalysts. The activity significantly depends on the acid-base properties of the catalyst.

Dendritic fibrous nano-silica supported gold nanoparticles as an artificial enzyme

2018 ◽  
Vol 6 (11) ◽  
pp. 1600-1604 ◽  
Author(s):  
Rustam Singh ◽  
Rajesh Belgamwar ◽  
Mahak Dhiman ◽  
Vivek Polshettiwar
Keyword(s):  
Gold Nanoparticles ◽  
Enzymatic Activity ◽  
Oxidation Product ◽  
Artificial Enzyme ◽  
Nano Silica ◽  
Unique Role ◽  
Fibrous Morphology ◽  
Supported Gold Nanoparticles ◽  
Supported Gold

We report a dendritic fibrous nano-silica supported gold nanoparticles (DFNS/Au) as peroxidase like artificial enzyme. This study indicates the unique role of fibrous morphology of DFNS for enhancement in enzymatic activity. A solvent dependent selectivity towards a two-electron oxidation product, TMB-diamine, has also been observed.

Ultra-fast Cu-based A3-coupling catalysts: faceted Cu2O microcrystals as efficient catalyst-delivery systems in batch and flow conditions

2021 ◽  
Author(s):  
Huizhi Bao ◽  
Alain Y. Li ◽  
Vanessa Kairouz ◽  
Audrey Moores
Keyword(s):  
Flow Reactor ◽  
Reaction Medium ◽  
Loading Conditions ◽  
Thermal Heating ◽  
Flow Conditions ◽  
Efficient Catalyst ◽  
Cu Contamination ◽  
Drug Synthesis ◽  
A3 Coupling

Cu(I) catalysts were studied for the synthesis of a propargylamine via A3-coupling of aldehyde, amine, and alkyne, under solvent-free and low loading conditions, using batch microwave or flow thermal heating. We explore ultra-low loading conditions with Cu(I) salts as ultra fast and active catalysts featuring TOFs above 105 h-1. Well-defined octahedral and cubic Cu2O microcrystals were also successfully applied and compared to this reaction. Both types of microcrystals exhibited excellent catalytic activities within minutes, via in-situ generation of low dose of Cu(I) ions within the reaction medium, to achieve TON beyond 2000 and recycling up to 10 times in a flow reactor. The study of the catalytic system demonstrated that the activity was surface-structure dependent and allowed for the design of low Cu contamination A3-coupling systems, affording a product at the decigram scale, with Cu contamination below FDA recommendations for drug synthesis, without the need for a purification procedure.

ChemInform Abstract: Cobalt Oxide Supported Gold Nanoparticles as a Stable and Readily-Prepared Precursor for the in situ Generation of Cobalt Carbonyl Like Species.

ChemInform ◽  
2012 ◽  
Vol 43 (15) ◽  
pp. no-no
Author(s):  
Akiyuki Hamasaki ◽  
Akiko Muto ◽  
Shingo Haraguchi ◽  
Xiaohao Liu ◽  
Takanori Sakakibara ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cobalt Oxide ◽  
Cobalt Carbonyl ◽  
In Situ Generation ◽  
Supported Gold Nanoparticles ◽  
Supported Gold

Vital Role of Moisture in the Catalytic Activity of Supported Gold Nanoparticles

2004 ◽  
Vol 116 (16) ◽  
pp. 2181-2184 ◽  
Author(s):  
Masakazu Daté ◽  
Mitsutaka Okumura ◽  
Susumu Tsubota ◽  
Masatake Haruta
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Vital Role ◽  
Supported Gold Nanoparticles ◽  
Supported Gold
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