Table 2. Parameters and results of
determining reaction order
The reason for this fractional order reaction between
CH3I and Ag0-Aerogel is not determined
yet. This fractional-reaction order was also observed in other
silver-containing materials. Zhou and White55suggested that the desorption of organic products from Ag(111) surface
changes the reaction order and Robb and Harriott56indicated that the diffusion limitation in supported silver catalysts
does. Therefore, the fractional reaction order maybe not only caused by
the specific reaction mechanism but also the physical process.
Nth Order SCM
Examination and
Application
The effectiveness of the nth order SCM can be
demonstrated by comparing predictions made by the nthorder SCM and 1st order SCM with averageks , which the average ks =
0.195 cm/s was calculated by averaging 4 ks ’s
directly. Figure 6 shows the prediction of 113 ppbv CH3I
adsorption behavior generated by using nth order SCM
and 1st order SCM with averageks . Comparing with 1st order
SCM with average ks , the nthorder SCM decreases AARD by approximately 175%. The mass uptakes in 288
hours predicted by using nth order SCM and
1st order SCM with average kswere 0.24 wt% and 0.59 wt% respectively, where the measured mass
uptake is approximately 0.17 wt%.