At 46 percent of the mass, oxygen is the most plentiful element inEarth’scrust. The proportion of oxygen by volume in the atmosphere is 21 percent and by weight inseawateris 89 percent. In rocks, it is combined with metals and nonmetals in the form of oxides that are acidic (such as...
Further protonation/reduction converts the OOHad into Oad and H2Oad, where the Oad on the Pt surface continues to react following the dissociative mechanism. Currently, the state-of-the-art catalyst for the ORR in the fuel cell is the carbon-supported Pt NPs. In order to study size-...
1O2canlast for 4μs in water and 100μs in a nonpolar environment [1]. 1O2 reacts with most of the biological molecules at near di?usion-controlled rates [1]. It directly oxidizes protein, unsaturated fatty acids, and DNA [32]. It causes nucleic acid modi?cation through selective ...
video footage was recorded of the electrode face and side. A selection of front-angle frames at four hypergravity levels is shown in Fig.4a, where the size of bubbles on the surface appears to decrease with increasing g-level. Frames showing 0–18 s at each ...
352M.P.Gomes&Q.S.Garciainate from non-enzymatic reactions such as lipid per-oxidation that occur even with very low moisture con-tents (McDonald 1999) and from Amadori and Mail-lardreactions(Sun&Leopold1995).Inhydratedseeds,however, all metabolically activate compartments maybecome sources of RO...
Fig. 3.XPS spectra of B-1 and N-12.5 for (c) O 1 s[65]. Non-metal doping can also induce the formation of oxygen vacancies, and the most studied element is N. Theoretical calculations show that the doping of N can induce the reduction of oxygen vacancy formation energy which promotes...
Hydroxyl and superoxide radicals generated at the end of both steps then react with organic pollutants in aqueous solution. Evolution of CEC efficiency under various revolution speeds The revolution speed is a crucial parameter in ball milling that significantly affects the impact mode/energy among ...
(e−) transfers to the electrode can react with the H+or H2O in acidic or alkaline solution on a void active site of the catalyst to produce the adsorbed hydrogen atoms (Hads) (Eq. (1) or (2)). Subsequently, the second step is associated with desorption and accumulation of the H...
Oxygen-containing carbons are promising supports and metal-free catalysts for many reactions. However, distinguishing the role of various oxygen functional groups and quantifying and tuning each functionality is still difficult. Here we investigate the r
Similarly, maxima in the production rates coincided with minima in the ESEM average image intensities. Fig. 3: Self-sustained oscillations of DRM occurred on a Ni catalyst. a, Time series of the temperature, reactor pressure, average image intensities and mass spectrometry signals of reactants ...