Fast tracer desorption

Fast Tracer Desorption There are many zeolitic systems in which intracrystalline diffusion is too slow to measure directly by the PFG method. A modification of this method which makes it possible, under certain conditions, to measure much slower diffusion processes has recently been introduced by Karger(28,29),... 

With the development of the fast tracer desorption NMR method a more detailed investigation of these systems became possible. A study of diffusion of C2H6 in 5A by this method showed no significant surface barrier, even when the sieve was dehydrated at 600°C under conditions similar to those used commercially(28,29). 

Thus the p.d.f for nonadsorbing tracers can be used directly to estimate the p.d.f. of sojourn times on the catalyst surface if the partition coefficient, K, for the reactant is known and adsorption-desorption is fast. 

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