TAP experiment design

MBS experiments obtain essential kinetic and mechanistic information by modulating the reactant flux and measuring the shift in arrival times at the detector between scattered 

In the TAP reactor system the reactor can be isolated from the vacuum system via a slide valve. When the slide valve is closed, the microreactor can be operated as a continuous plug flow-type 

The input pulse in a TAP experiment typically contains only 10 nmol of reactant, and the local pressure in the reaction zone may reach ca. 10 torr during a pulse. In a packed reactor, the mean free path is ca. 4000 pm, which is significantly larger than the space between particles. As a result, in a packed-bed reactor, molecules collide with particles, but seldom with one another. 

At sufficiently small pulse intensities, a one-pulse TAP experiment can be considered a state-defining experiment, since the number of molecules in a reactant pulse is typically much smaller (10 -10 times smaller) than the number of surface atoms in the catalyst sample being probed [82]. As a result, the reactant pulse does not significantly perturb the catalyst surface. 

There are three basic concepts that distinguish TAP from other kinetic experiments and form the basis for extracting kinetic information from TAP pulse response data  

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