A new reactor model for TAP pulse response experiments called a 'thin-zone reactor' is developed and applied to irreversible adsorption/reaction and reversible adsorption. In a thin-zone reactor, concentration gradients across the catalyst bed can be neglected, and diffusion and chemical reaction can be separated. The expressions for kinetic parameters fora thin-zone reactor can be calculated using moments, and are much simpler than the expressions for a one-zone or a three-zone reactor. The thin-zone model is particularly useful for investigating fast chemical reactions, since the extent of reaction can be controlled by the thickness and position of the catalyst zone. The expression for conversion in the case of irreversible adsorption/reaction in a thin-zone reactor is governed by a relationship that is analogous to the expression for first-order reaction in a CSTR. Moment based 'fingerprints' are defined for irreversible adsorption, reversible adsorption, and diffusion. The thin-zone model is used to determine kinetic parameters for the oxidation of propene over a VPO catalyst.