Elucidating complex catalytic mechanisms based on transient pulse-response kinetic data

• A new strategy was developed for discriminating between catalytic reaction mechanisms.
• This strategy is based on temporal coherency of transient kinetic data.
• Transient kinetic data include the net production rates R and gas concentrations C.
• The R–C data were obtained from thin-zone TAP experiments via the Y-Procedure.

We describe a strategy for discriminating reaction mechanisms based on the non-steady-state coherency of kinetic characteristics including net production rates as well as gas and surface concentrations. The suggested strategy of mechanism discrimination utilizes two novel concepts: instantaneous surface storages and temporal kinetic coherency. The first concept is used to express the catalyst composition during transient experiments through gaseous transformation rates, while the second concept is used to test whether a hypothetical reaction mechanism is consistent with observed kinetic characteristics. In our study, these kinetic characteristics are made available by analyzing exit-flow rate data of Thin-Zone Temporal Analysis of Products (TAP) pulse-response experiments via an algorithm called the Y-Procedure. To illustrate our mechanism discrimination strategy, we used a prototypical multi-route CO oxidation mechanism. The constructed decision tree can be used to distinguish between multiple variations of this mechanism.