Ethanol oxidation has been studied on Pt(111), Pt(100) and Pt(110) electrodes in order to investigate the effect of the surface structure and adsorbing anions using electrochemical and FTIR techniques. The results indicate that the surface structure and anion adsorption affect significantly the reactivity of the electrode. Thus, the main product of the oxidation of ethanol on the Pt(111) electrode is acetic acid, and acetaldehyde is formed as secondary product. Moreover, the amount of CO formed is very small, and probably associated with the defects present on the electrode surface. For that reason, the amount of CO2 is also small. This electrode has the highest catalytic activity for the formation of acetic acid in perchloric acid. However, the formation of acetic acid is inhibited by the presence of specifically adsorbed anions, such as (bi)sulfate or acetate, which is the result of the formation of acetic acid. On the other hand, CO is readily formed at low potentials on the Pt(100) electrode, blocking completely the surface. Between 0.65 and 0.80 V, the CO layer is oxidized and the production of acetaldehyde and acetic acid is detected. The Pt(110) electrode displays the highest catalytic activity for the splitting of the C-C bond. Reactions giving rise to CO formation, from either ethanol or acetaldehyde, occur at high rate at any potential. On the other hand, the oxidation of acetaldehyde to acetic acid has probably the lower reaction rate of the three basal planes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/b802160k | DOI Listing |
Anal Chem
January 2025
The Jiangxi Province Key Laboratory for Diagnosis, Treatment, and Rehabilitation of cancer in Chinese Medicine, Jiangxi University of Chinese Medicine, Nanchang 330004, P. R. China.
An online reactive internal extraction electrospray ionization (iEESI) method was developed for the rapid determination of organic and inorganic speciation information for selenium in poultry tissue samples without complex sample pretreatment. The addition of citric acid as a reducing agent to the internal extraction solvent of methanol/acetic acid (99:1, V/V) for iEESI resulted in the reduction of selenate in the sample to selenite, accompanied by the production of malic acid as an oxidation product. The quantitative analysis of selenate was conducted by using malic acid.
View Article and Find Full Text PDFNutrients
December 2024
IFF, Health & Biosciences, Sokeritehtaantie 20, 02460 Kantvik, Finland.
Background/objectives: Ergothioneine (EGT) is an effective antioxidant that animals cannot produce and has an important anti-inflammatory role in cell protection, which can help lower the risk of various diseases. In this study, we investigated the potential role of gut microbiota in the production of EGT, which was found to increase in the mouse liver after dietary supplementation with betaine (BET) or polydextrose (PDX).
Methods: The effects of BET and PDX on the gut microbiota and tissue EGT content were investigated using a diet-induced obese mouse model and simulated fermentation in the human colon.
Nutrients
December 2024
Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria, SP 8 Monserrato, 09042 Cagliari, Italy.
Background: Sour taste is associated with acid-base homeostasis, which is critical to cell metabolism and health conditions. Vinegar, which contains acetic acid as the main component, is a sour food considered the second most common condiment in Italy.
Objectives: The aim of the study was to assess differences in sourness perception in subjects with olfactory deficits compared to controls and evaluate myrtle aromatization's potential effect in modulating sourness perception in subjects with hyposmia.
Nutrients
December 2024
Department of Gastroenterology and Hepatology, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland.
Background/objectives: Crohn's disease is known for being associated with an abnormal composition of the bacterial flora, dysbiosis and intestinal function disorders. Metabolites produced by gut microbiota play a pivotal role in the pathogenesis of CD, and the presence of unspecific extraintestinal manifestations.
Methods: The aim of this study was a determination of the level of bacterial metabolites in blood plasma in patients with Crohn's disease.
Foods
January 2025
Department of Oenology and Chemistry, Technical University of Moldova, 2004 Chisinau, Moldova.
and belong to acetic acid bacteria (AAB), associated with wine spoilage. The timely detection of AAB, thought essential for their control, is however challenging due to the difficulties of their isolation. Thus, it would be advantageous to detect them using molecular methods at all stages of winemaking and storage.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!