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Oxygen

About: Oxygen is a(n) research topic. Over the lifetime, 48149 publication(s) have been published within this topic receiving 1113788 citation(s). The topic is also known as: O & Oxygen.

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Papers
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Journal ArticleDOI: 10.1021/JP047349J
Abstract: We present a method for calculating the stability of reaction intermediates of electrochemical processes on the basis of electronic structure calculations. We used that method in combination with detailed density functional calculations to develop a detailed description of the free-energy landscape of the electrochemical oxygen reduction reaction over Pt(111) as a function of applied bias. This allowed us to identify the origin of the overpotential found for this reaction. Adsorbed oxygen and hydroxyl are found to be very stable intermediates at potentials close to equilibrium, and the calculated rate constant for the activated proton/electron transfer to adsorbed oxygen or hydroxyl can account quantitatively for the observed kinetics. On the basis of a database of calculated oxygen and hydroxyl adsorption energies, the trends in the oxygen reduction rate for a large number of different transition and noble metals can be accounted for. Alternative reaction mechanisms involving proton/electron transfer to ...

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Topics: Overpotential (59%), Reaction rate constant (57%), Oxygen (53%) ...read more

5,473 Citations


Open accessJournal ArticleDOI: 10.1042/BJ2190001
Topics: Oxygen toxicity (58%), Oxygen (58%), Radical (51%)

5,078 Citations


Open accessJournal ArticleDOI: 10.1021/NN901850U
15 Feb 2010-ACS Nano
Abstract: Nitrogen-doped graphene (N-graphene) was synthesized by chemical vapor deposition of methane in the presence of ammonia. The resultant N-graphene was demonstrated to act as a metal-free electrode with a much better electrocatalytic activity, long-term operation stability, and tolerance to crossover effect than platinum for oxygen reduction via a four-electron pathway in alkaline fuel cells. To the best of our knowledge, this is the first report on the use of graphene and its derivatives as metal-free catalysts for oxygen reduction. The important role of N-doping to oxygen reduction reaction (ORR) can be applied to various carbon materials for the development of other metal-free efficient ORR catalysts for fuel cell applications, even new catalytic materials for applications beyond fuel cells.

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Topics: Direct-ethanol fuel cell (62%), Electrocatalyst (60%), Catalysis (53%) ...read more

3,360 Citations


Journal ArticleDOI: 10.1126/SCIENCE.1162018
Matthew W. Kanan1, Daniel G. Nocera1Institutions (1)
22 Aug 2008-Science
Abstract: The utilization of solar energy on a large scale requires its storage. In natural photosynthesis, energy from sunlight is used to rearrange the bonds of water to oxygen and hydrogen equivalents. The realization of artificial systems that perform "water splitting" requires catalysts that produce oxygen from water without the need for excessive driving potentials. Here we report such a catalyst that forms upon the oxidative polarization of an inert indium tin oxide electrode in phosphate-buffered water containing cobalt (II) ions. A variety of analytical techniques indicates the presence of phosphate in an approximate 1:2 ratio with cobalt in this material. The pH dependence of the catalytic activity also implicates the hydrogen phosphate ion as the proton acceptor in the oxygen-producing reaction. This catalyst not only forms in situ from earth-abundant materials but also operates in neutral water under ambient conditions.

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Topics: Water splitting (63%), Cobalt phosphate (60%), Catalysis (55%) ...read more

3,351 Citations


Open accessJournal ArticleDOI: 10.1021/BI00745A020
09 Oct 1973-Biochemistry
Abstract: Quenching of the fluorescence of various fluorophores by molecular oxygen has been studied in aqueous and nonaqueous solutions equilibrated with oxygen pressures up to 100 atm. Temperature dependence of quenching, agreement with the Stern–Volmer equation, and fluorescence lifetime measurements indicate that essentially all the observed quenching is dynamic and close to the diffusion-controlled limits. Studies of charged polyamino acids containing tryptophan show that oxygen quenching, in contrast to I−, is completely insensitive to charge effects. Ethidium bromide, when intercalated into double helical DNA, is quenched with 1/30th of the efficiency of the free dye in solution. Three dyes bound to bovine serum albumin were also found to be relatively protected from the free diffusion of oxygen. Quenching of intrinsic or bound fluorophores by molecular oxygen is therefore an appropriate method to determine the accessibility to oxygen of regions of the macromolecule surrounding the fluorophore and indirectly the structural fluctuations in the macromolecule that permit its diffusion to the fluorophore.

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Topics: Quenching (55%), Fluorophore (54%), Oxygen (52%) ...read more

2,300 Citations


Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202279
20211,114
20201,160
20191,190
20181,152
20171,079

Top Attributes

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Topic's top 5 most impactful authors

Vladislav V. Kharton

81 papers, 3.7K citations

Tobias Mattisson

78 papers, 7.1K citations

Anders Lyngfelt

68 papers, 6.3K citations

Robert J. Madix

45 papers, 3.1K citations

Mikhail V. Patrakeev

44 papers, 1.1K citations

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