Hydrogen adsorption oxidation

Markovic NM, Schmidt TJ, Grgur BN, Gasteiger HA, Behm RJ, Ross PN. 1999. The effect of temperature on the surface process at the Pt(lll)-liquid interface Hydrogen adsorption, oxide formation and CO oxidation. J Phys Chem B 103 8568. 

Markovic, N.M., Schmidt, T.J., Grgur, B.N. et al. (1999) Effect of temperature on surface processes at the Pt(l 11 )-liquid interface hydrogen adsorption, oxide formation, and CO oxidation. Journal of Physical Chemistry B, 103, 8568-8577. 

Figure 12.5 CO stripping voltammogram with a CO- tee 0.1 M H2SO4 electrolyte. Compare the data in Fig. 12.4 the CO oxidation region begins at V = 0.43 V. After CO stripping, hydrogen adsorption/desorption peaks and the beginning of the Pt oxidation range are shown.

The second most widely used noble metal for preparation of electrodes is gold. Similar to Pt, the gold electrode, contacted with aqueous electrolyte, is covered in a broad range of anodic potentials with an oxide film. On the other hand, the hydrogen adsorption/desorption peaks are absent on the cyclic voltammogram of a gold electrode in aqueous electrolytes, and the electrocatalytic activity for most charge transfer reactions is considerably lower in comparison with that of platinum. 

Several methods are available to remove gasoline constituents from water, such as air stripping, biorestoration, activated carbon adsorption, reverse osmosis, ozonation, oxidation, resin adsorption, oxidation with hydrogen peroxide, ultraviolet irradiation, flotation, and land treatment. 

Over zinc oxide it is clear that only a limited number of sites are capable of type I hydrogen adsorption. This adsorption on a Zn—O pair site is rapid with a half-time of less than 1 min hence, it is fast enough so that H2-D2 equilibration (half-time 8 min) can readily occur via type I adsorption. If the active sites were clustered, one might expect the reaction of ethylene with H2-D2 mixtures to yield results similar to those obtained for the corresponding reaction with butyne-2 over palladium That is, despite the clean dideutero addition of deuterium to ethylene, the eth-... 

Hydrogen adsorption and oxidation of formic acid show a pronounced dependence on the structure of single crystal surfaces. The influence of the terrace and step orientation and step density is reflected in both reactions on step surfaces. The multiple states of hydrogen adsorption can be correlated with the nature of adsorption sites. 

Oxidation of formic acid shows a pronounced structural dependence which is well illustrated by data on the low index planes (8-10) and preliminary data on stepped single crystal surfaces (11). In this work further investigations of hydrogen adsorption and oxidation of formic acid on single crystal Pt surfaces with 15 orientations are reported. 

Both the data on hydrogen adsorption and formic acid oxidation show pronounced structural sensitivity, thus confirming a paramount role of surface structure in electrocatalytic reactions. It can be concluded that each crystallographic orientation represents a distinct electrochemical (chemical) entity. The investigation of stepped surfaces seems to be necessary to reach an understanding of these systems on a molecular level. Hydrogen adsorption shows dependences on the terrace orientation, step orientation, and step density. All the... 

Bandosz TJ. On the adsorption/oxidation of hydrogen sulfide on unmodified activated carbons at ambient temperatures,/. Coll. Interface. 2002, 246,1-20. 

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