DETERMINATION OF REACTIVITY DISTRIBUTIONS FROM STEADY-STATE ISOTOPIC TRANSIENT DATA - A MODEL STUDY

The potential of different mathematical methods for the recovery of re activity distributions, f(k), from steady-state isotopic transient kin etic analysis (SSITKA) data has been tested and compared using a model catalyst system that consisted of a mechanical mixture of two catalys ts with catalytic sites of known and different reactivity. Fitting one or two exponential functions to the measured transients confirmed the presence of two different pools of reaction intermediates, but the us e of this method for determination of f(k) is limited to simple cataly tic systems. For more complicated systems, the Tikhonov/Fredholm metho d might be superior to the inverse Laplace transform method. (C) 1998 Elsevier Science B.V.