A new technique is presented for the investigation of non-stationary reaction systems. Reliable quantitative information is obtained for the description of non-stationary operation. A detailed description of the reaction mechanism is possible and different mechanisms with the same steady-state behavior can be discriminated. Two models for the evaluation are presented, an analytical expression for a fast parameter determination and a rigorous approach for the determination of the elementary kinetic expressions. The new technique is used for the investigation of the total combustion of diluted methane on a Pd-support catalyst. A Langmuir-Hinshelwood mechanism was found, a Eley-Rideal mechanism could be excluded. The detailed chemical mechanism is presented and kinetic constants for the elementary steps are determined.