First-principles approach to in-situ model catalyst studies

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The purpose of in-situ studies of well-defined single-crystal model catalysts is to transport the rigorous atomic-scale understanding inherent to the ultra-high vacuum Surface Science approach to technologically relevant near-ambient conditions. In corresponding feeds and at typically much higher conversion rates heat and mass transfer limitations in the gas-surface system become increasingly important. Such flow effects in the complex in-situ reactor geometries need to be carefully understood, controlled and at best disentangled to reach the aspired molecular-level understanding of the on-going surface chemistry. In the present project we propose to complement these endeavors by advancing a first-principles based multiscale modeling approach that ranges from the elementary surface catalytic processes to the macro-scale flow profiles. By integrating first-principles kinetic Monte Carlo (1pkMC) microkinetic descriptions into the OpenFoam/CatalyticFoam computational fluid dynamics package we specifically want to generate publicly available general-purpose methodology that can explicitly describe the reaction-transport coupling in fully resolved in-situ reactor geometries. On the materials gap side the approach will be extended from single crystals towards model catalysts featuring nanoparticles on a planar support. For both strands we expect even more and intricate transfer limitations than demonstrated in our preceding work on idealized flow geometries. The conceptual discussion and development will further close the gap between physico-chemical and chemical-engineering type research in heterogeneous catalysis. In addition, the established 1pkMC-flow framework will be employed to quantitatively model in-situ X-ray photoelectron spectroscopy data for CO oxidation on Pd(100).