(764b) Modeling phase formation on catalyst surfaces: Coke formation andsuppression in hydrocarbon environments
AIChE Annual Meeting
2021
2021 Annual Meeting
Liaison Functions
AIChE Journal Futures: New Directions in Chemical Engineering Research (Invited Talks)
Tuesday, November 9, 2021 - 3:55pm to 4:20pm
grand canonical Monte Carlo (GCMC) to study coke formation on Fe-based catalysts during
propane dehydrogenation (PDH). As expected, pure Fe surfaces develop stable graphitic coke
structures and rapidly deactivate. We find that coke formation is markedly less favorable on Fe3C and FeS surfaces. Fe-Al alloys display varying degrees of coke resistance, depending on their composition, suggesting that they can be optimized for coke resistance under PDH conditions. Electronic structure analyses show that both electron-withdrawing effects (on Fe3C and FeS) and electron-donating effects (on Fe-Al alloys) destabilize adsorbed carbon. On the alloy surfaces, a geometric effect also isolates Fe sites and disrupts the formation of graphitic carbon networks. This work demonstrates the utility of GCMC for studying the formation of disordered phases on catalyst surfaces and provides insights for improving the coke resistance of Fe-based PDH catalysts.