Taming Complexity in Heterogeneous Catalysis Using Pulsed Flow and Transient Spectroscopy

A precise understanding of heterogeneous catalyst structure and activity is required to design more efficient, greener, industrial chemical processes. In-depth insight into structure-activity-relationships is possible using idealised model systems in precisely controlled environments, but the significant complexity of industrial catalytic systems makes the direct application of this knowledge difficult. Herein, we demonstrate that precise environmental control is possible over non-idealised catalytic materials in complex environments. We find that ambient pressure pulsed flow and transient spectroscopy experiments of CO oxidation over a powdered Pd/-Al2O3 catalyst accurately recreate the transient activity and coverage dependencies measured in ultra-high vacuum over Pd/Al2O3/NiAl(110) and Pd(111) single crystal systems. Numerical simulations using the kinetics established over single crystal systems quantitatively predicts the transient and steady-state activity and recreates the coverage dependencies in CO rich environments, confirming the state of the Pd/-Al2O3 catalyst is consistent with Pd(111). This successful combination of techniques is broadly applicable, affording a direct bridging of the complexity gap in heterogeneous catalysis, and providing a pathway to more efficient catalyst design.