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Electrochemical loading

The conditions encountered in studying the stability of catalysts under electrochemical load are very complicated. Stability depends strongly on the potential and on the nature of the working substance. For example, pure CoTAA, when used as an oxygen catalyst at potentials of about 800 mV, is active only for a period of some hours. If, however, it is used in the anode for the oxidation of formic acid at 350 mV, it will give more than 6 months (4000 hours ) continuous service under the same conditions. [Pg.164]

It is assumed that the slip dissolution mechanism [40] adequately describes the crack-tip process. The controlling variables are the stress intensity factor (from mechanical loading) and the crack-tip electrode potential (from electrochemical loading). The crack-tip repassivation process is important, because the kinetics of repassivation determine the fraction of the crack-tip area that remains bare over a slip-dissolution-repassivation cycle. The temperature dependence of the crack-tip process is brought into play through a temperature-dependent crack-tip strain... [Pg.681]

Most of the time, metal/dielectric nanocomposites are studied in the form of solutions or thin solid films on a substrate Colloids, doped and annealed glasses, sol-gels, surfactant-stabilized nanoparticles, micelles, two- or three-dimension self-assembled nanocomposites, self-organized mesoporous oxides filled with metals, electrochemically-loaded template membranes, metal-ion implanted crystals, nanocomposite films elaborated by laser ablation, cluster-beam deposition, radio-frequency sputtering, or nanolithography. [Pg.480]

During each run, the membrane is electrochemically loaded with hydrogen from the left side with a constant electrolysis current of 30 mA. The initial potential of the palladium/palladium hydride (vs. Ag/AgCl reference electrode) on carbon dioxide reaction side at the start of the run is defined as E. This potential depends on the hydride content of the membrane and the equilibrium between the metal hydride/bicarbonate solution. [Pg.150]

Fig. 7.27 Optical transmission of a 40 nm thick Mg-Ni-Hx film evaporated on ITO/glass and capped with 5nm Pd during electrochemical loading/unloading cycles in... Fig. 7.27 Optical transmission of a 40 nm thick Mg-Ni-Hx film evaporated on ITO/glass and capped with 5nm Pd during electrochemical loading/unloading cycles in...
If the polarization induced by the decreasing electrochemical performance during the electrochemical loading increases significantly above 100 mV, the electrode rapidly loses its electrochemical performance, shown for the lifetime curve of a type 1 electrode with an operation time of 1200 h. [Pg.117]

Fig. 36 shows the time evolution of the electrode potential and transmittance during the initial galvanostatic loading of a Pd (15 nm) capped Sm (67 nm) film hydrogenated via electrochemical loading in 5 M NaOH (von Rottkay et al., 1999a). Two plateaus were observed, one at —690 mV and another one at —820 mV, after which the potential was observed to drop... [Pg.129]

The modifications in the hydrogen induced optical, electronic and structural properties of Gd-Mg alloy films have been studied by utilizing both the gas phase loading as well as electrochemical loading. The Gdi Mg alloy films (200 nm) with 0.1 < z < 0.9, capped with... [Pg.241]

The use of lower temperatures will also slow the rate of most chemical degradation processes and so should also increase cell and stack hfe. The lower temperature will slow difliisional processes such as grain coarsening and diffusion across interfaces, which can lead to solid state reactions. However, some impurities may not be removed at these lower temperatures building up on the electrodes leading to degradation. It should also be noted that lower performance at lower temperatures may necessitate the use of higher electrochemical loads than would be required for optimal durability. [Pg.165]


See other pages where Electrochemical loading is mentioned: [Pg.30]    [Pg.266]    [Pg.229]    [Pg.83]    [Pg.93]    [Pg.93]    [Pg.98]    [Pg.99]    [Pg.99]    [Pg.103]    [Pg.104]    [Pg.104]    [Pg.105]    [Pg.105]    [Pg.111]    [Pg.116]    [Pg.118]    [Pg.129]    [Pg.131]    [Pg.136]    [Pg.139]    [Pg.181]    [Pg.182]    [Pg.239]    [Pg.244]    [Pg.267]   
See also in sourсe #XX -- [ Pg.266 ]

See also in sourсe #XX -- [ Pg.93 , Pg.99 , Pg.103 , Pg.104 , Pg.129 ]




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