The Y-Procedure methodology for the interpretation of transient kinetic data: Analysis of irreversible adsorption

This paper deals with the analysis of transient kinetic data obtained in the Thin-Zone (TZ) configuration of the Temporal Analysis of Products (TAP) reactor. The Y-procedure that reconstructs the reaction rate and gas composition in the catalytic zone with no assumptions on the reaction mechanism (Yablonsky et al., 2007) was applied to irreversible adsorption with coverage-dependent kinetic coefficients. We have used the Y-Procedure analysis to develop a novel framework for the interpretation of non-steady-state kinetic data. This framework was illustrated by multiple numerical examples concerning irreversible adsorption, and by experimental data corresponding to oxygen adsorption on polycrystalline platinum. The total concentration of active sites was estimated as 6×10−7mol/gcat. It was found that for the surface coverage up to 0.8, kinetics followed the dissociative adsorption model with an intrinsic adsorption constant of 1.12×106m3/mol/s. Kinetic parameters estimated via the Y-procedure agreed well with the values obtained via the moment analysis. The methodology developed in this paper will guide the systematic application of the Y-Procedure analysis to more complex catalytic systems.

► We extended the Y-Procedure analysis of TAP data to irreversible adsorption.
► The evolution of surface intermediates was calculated from the reaction rates.
► The concentration of active sites was estimated from a single state- altering pulse.
► The analysis was applied to oxygen uptake on polycrystalline Pt.