Active site high-temperature pyrolysis

Our data can be used to estimate the effective temperatures reached in each site through comparative rate thermometry, a technique developed for similar use in shock tube chemistry (32). Using the sonochemical kinetic data in combination with the activation parameters recently determined by high temperature gas phase laser pyrolysis (33), the effective temperature of each site can then be calculated (8),(34) the gas phase reaction zone effective temperature is 5200 650°K, and the liquid phase effective temperature is 1900°K. Using a simple thermal conduction model, the liquid reaction zone is estimated to be 200 nm thick and to have a lifetime of less than 2 usee, as shown in Figure 3. 

Lefevre, M., J.P. Dodelet, and P. Bertrand (2000). O2 reduction in PEM fuel cells Activity and active site structural information for catalysts obtained by the pyrolysis of high temperature of Fe precursors. J. Phys. Chem. B 104, 11238-11247. 

Following the discovery of the two important factors (the N and micropore contents) that govern the activity of catalysts made by the impregnation of a carbon black with 0.2 wt% Fe as iron acetate and its pyrolysis in NH3 at high temperature, in 2008, we proposed a structure that would replace FeN2/C, the incomplete catalytic site structure depicted in Fig. 10.4 that was previously introduced as a possible part of the most active type of catalytic site. 

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