Evolution catalysts

Thurgood CP, et al. Deactivation of Cu/ZnO/AECC catalyst evolution of site concentrations with time. Top Catal. 2003 22(3 4) 253-9. 

It should be recognized that the derived parameter set is not unique because of the scatter in experimental consumption transients (i.e. Figure 2.22), equally good fits to the q-i and i-t SPS-PEG-C1 data yield a locus of kinc(q) and q(q) parameters [12]. Further study and refinement of the derivatization procedure should help clarify the source of the experimental dispersion. In addition, different combinations of parameters yield distinct predictions for the catalyst evolution so that surface analytical experiments should help narrow the selection. Despite these uncertainties, a correct description of the SPS-PEG-C1 system clearly includes both potential dependent adsorption and deactivation processes. This conclusion is reinforced by multicycle voltammetry where the potential dependence of adsorption that is most significant at large overpotentials is convolved with consumption that dominates catalyst evolution at low overpotentials. 

For shape change simulations a general statement of catalyst evolution on the moving interface includes SPS adsorption, consumption (Equation 2.22) and area changes associated with the interface motion (Equation 2.4). 

Table 17.1 gives a brief summary of PP catalyst evolution. 

Catalyst evolution. As stated above, the reaction is accompanied by a Pd dissolution/re-precipitation process (16.) This catalyst evolution is also reflected by Transmission Electron Microscopy (TEM) investigations of catalyst 3W before and after die reaction (Figure 3.)... 

Malesevic, A., Chen, H., Hauffman, T, et al Study of the catalyst evolution during annealing preceding the growth of carbon nanotubes by microwave plasma-enhanced chemical vapour deposition. Nanotechnology 18(45), 455602 (2007)... 

The catalyst evolution for Ford s U.S. medium-duty diesel trucks included a migration from low or no precious metal DOCs to Pt-rich DOCs, and Anally to... 

Saleh, R., Wachs, L, Chan, S., etal. (1986). The Interaction of V2O5 with Ti02(anatase) Catalyst Evolution with Calcination Temperature and o-Xylene Oxidation, J. Catal, 98, pp. 102-114. 

Pd supported catalysts Evolution of the support during Pd deposition and K doping... 

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