Oxygen

About: Oxygen is a research topic. Over the lifetime, 48149 publications have been published within this topic receiving 1113788 citations. The topic is also known as: O & Oxygen.

Antioxidants in Nutrition, Health, and Disease

Abstract: i) Oxygen, the breath of life or oxygen, the first toxic oxidizing air pollutant ii) Metals and oxygen: Respiration, oxidation, and oxygen toxicity iii) Antioxidants: elixirs of life or media hype v) Oxidative stress vi) Free radicals and antioxidants in ageing and disease: Fact or fantasy? vii) Free radicals and cardiovascular disease

Relationship between Oxygen Defects and the Photocatalytic Property of ZnO Nanocrystals in Nafion Membranes

Abstract: ZnO nanocrystals with different oxygen defects (type and concentration) are successfully prepared via the templating method in Nafion membranes. Photoluminescence and infrared characterizations reveal that the concentration of oxygen defects (oxygen vacancy and interstitial oxygen) is quite different for the samples prepared via different synthesis processes. Photocatalytic activity measurements show that the sample with a higher amount of oxygen defects exhibits excellent activity toward the degradation of rhodamine B. Compared with bulk ZnO, ZnO nanocrystals embedded in Nafion membranes have an antiphotocorrosion property. The possible photocatalytic mechanism is discussed in detail, and the oxygen defects are proposed to be the active sites of the ZnO photocatalyst.

Calorimetric heats for CO and oxygen adsorption and for the catalytic CO oxidation reaction on Pt{111}

Abstract: Single crystal adsorption calorimetry was applied to investigate the heats of adsorption of CO and oxygen and the reaction heats for the CO oxidation process on Pt{111} at room temperature Both sticking probabilities and heats of adsorption for CO and oxygen are presented as a function of coverage These results are used to interpret the subsequent measurements taken for the CO oxidation process on the same surface The initial heats of adsorption of CO and oxygen on Pt{111} are 180±8 and 339±32 kJ/mol, respectively In addition the pairwise lateral repulsive interaction between CO molecules in a (√3×√3)R30° ordered layer at θ=1/3 is found to be 4 kJ/mol A detailed Monte Carlo modeling of the dissociative adsorption and sticking probability of oxygen on Pt{111} is performed The initial rapid fall in heat is attributed to adsorption on defect sites, and subsequent adsorption on the planar {111} surface proceeds with a third neighbor interaction energy between the oxygen adatoms ω3∼22 kJ/mol When gaseou

Selective oxidation of alcohols to esters using heterogeneous Co3O4-N@C catalysts under mild conditions.

Abstract: Novel cobalt-based heterogeneous catalysts have been developed for the direct oxidative esterification of alcohols using molecular oxygen as benign oxidant. Pyrolysis of nitrogen-ligated cobalt(II) acetate supported on commercial carbon transforms typical homogeneous complexes to highly active and selective heterogeneous Co3O4-N@C materials. By applying these catalysts in the presence of oxygen, the cross and self-esterification of alcohols to esters proceeds in good to excellent yields.