Cracking the physical insight of power law models: Bridging the gap between macroscopic kinetics and surface coverages

Abstract

We propose a methodological framework to quantify the relative abundance of key surface intermediates via analysis of the macroscopic intrinsic kinetic characteristics of gas‐phase data. At the core of this approach is the development of analytical expressions, which link reaction orders and activation energies in macroscopic power law models to the fractional coverage of the non‐observable intermediates. Through the design of an advanced parameter estimation methodology, these relationships were further exploited to develop thermodynamically consistent and mechanistic‐based power law models which could capture the evolution of surface occupancy profiles along the reactor length. The developed framework was tested through in‐silico water gas shift reaction case‐studies; the results indicate the robustness of the approach and the mechanistic insight that can be gained from its application. The methodology proposed in this study could thus be of general value to assist in reaction mechanism analysis, identification of key surface intermediates, and reactor optimization.