Reactivity of the Gold/Water Interface During Selective Oxidation Catalysis

  title={Reactivity of the Gold/Water Interface During Selective Oxidation Catalysis},
  author={Bhushan N. Zope and David D. Hibbitts and Matthew Neurock and Robert J. Davis},
  pages={74 - 78}
Indirect Oxidation by Oxygen Partial oxidation of alcohols to aldehydes and ketones must avoid complete oxidation to carbon dioxide and water. Zope et al. (p. 74) examined the partial oxidation of ethanol and glycerol to acids in alkaline aqueous solvents over gold and platinum catalysts. Conversions were highest for gold supported on titania, but studies with isotopically labeled molecular oxygen showed that oxygen incorporated into the acid comes from hydroxide ions. Direct incorporation of… 

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The important role of hydroxyl for these two oxidation reactions catalyzed by gold, in terms of its influence on the turnover frequency is discussed, and the use of water as a "green" solvent becomes an attractive choice.

Oxygen and hydroxyl species induce multiple reaction pathways for the partial oxidation of allyl alcohol on gold.

Evidence is provided that the partial oxidation of allyl alcohol to its corresponding aldehyde, acrolein, over oxygen-precovered gold surfaces occurs via multiple reaction pathways, and this work may aid in the understanding of oxidative catalysis over gold and the effect of water therein.

Inhibition of gold and platinum catalysts by reactive intermediates produced in the selective oxidation of alcohols in liquid water

Solid catalysts containing supported nanoparticles of metals such as Au and Pt are very efficient in the oxidation of alcohols obtained from biorenewable sources under mild conditions. However, these

Selective Oxidation/Dehydrogenation Reactions

Gold catalysts were extensively studied in the selective oxidation of ethanol into acetic acid and ethyl acetate. Gold supported on titania was found to be the most promising catalysts, demonstrating

The critical role of water at the gold-titania interface in catalytic CO oxidation

It is shown through kinetics and infrared spectroscopy that the presence of water can lower the reaction activation barrier by enabling OOH groups to form from adsorbed oxygen (see the Perspective by Mullen and Mullins).

Selective oxidation of ethanol in the liquid phase over Au/TiO2

The selective oxidation of aqueous ethanol solutions with air over two commercial 1.5 and 1 wt% Au/TiO2 catalysts was investigated in six stirred mini‐autoclaves operated in parallel. The catalysts

Control of selectivity in allylic alcohol oxidation on gold surfaces: the role of oxygen adatoms and hydroxyl species.

The effects of oxygen adatoms and surface hydroxyls on the selectivity for oxidation of allylic alcohols (allyl alcohol and crotyl alcohol) on gold surfaces are discussed and results suggest that surface hydoxyls promote partial oxidation of allies alcohols to their corresponding aldehydes with very high selectivity.

Ambient base-free glycerol oxidation over bimetallic PdFe/SiO2 by in situ generated active oxygen species

Low temperature oxidation of alcohols over heterogeneous catalysts is exceptionally challenging, particularly under neutral conditions. Herein, we report on an efficient, base-free method to oxidise

Water Influences the Activity and Selectivity of Ceria-Supported Gold Catalysts for Oxidative Dehydrogenation and Esterification of Ethanol

In this study, we show that water influences the activity and selectivity of a ceria-supported gold catalyst for the oxidative dehydrogenation and esterification of ethanol in a fixed-bed flow

Promotional effect of hydroxyl on the aqueous phase oxidation of carbon monoxide and glycerol over supported Au catalysts

Gold particles supported on carbon and titania were explored as catalysts for oxidation of CO or glycerol by O2 at room temperature in liquid-phase water. Although Au/carbon catalysts were not active

Spin trapping of Au-H intermediate in the alcohol oxidation by supported and unsupported gold catalysts.

EPR spectroscopy and spin trapping results strongly suggest intermediate formation of Au-H species during alcohol oxidation, and confirm that the hydrogen in the spin adduct originates from the cleavage of the C-H bond in the alcohol molecule.

Catalyst parameters determining activity and selectivity of supported gold nanoparticles for the aerobic oxidation of alcohols: the molecular reaction mechanism.

A mechanistic proposal consisting of the formation of metal-alcoholate, beta-hydride shift from carbon to metal and M--H oxidation has been proposed that explains all experimental results.

Gold on Carbon as a New Catalyst for Selective Liquid Phase Oxidation of Diols

Catalytic oxidation of vicinal diols to α-hydroxy carboxylates with dioxygen in alkaline solution has been performed by using gold based catalysts. The optimization of the catalytic system has

Oxidation of alcohols with molecular oxygen on solid catalysts.

It is considered more feasible that the rate-deter-mining step is the cleavage of the C-H bond at the R-carbon atom, and the active site consists of an ensemble of metallic Auatoms and a cationic Au.