(685a) N2 Activation and Spillover on Single-Atom Alloy Catalysts: A Theoretical Study
AIChE Annual Meeting
2022
2022 Annual Meeting
Catalysis and Reaction Engineering Division
Nitrogen Chemistry: Thermal/photo/plasma N2 reduction
Friday, November 18, 2022 - 8:00am to 8:20am
Ammonia (NH3) is one of the most important feedstocks for the production of chemicals and fertilizer making it vital to the global economy at large. Activation of molecular nitrogen (N2) is seen as a critical step in the Haber-Bosch process, which is the ubiquitous industrial process for the production of ammonia. It has been shown that the activity of monometallic catalysts commonly used for ammonia synthesis is restricted by the scaling relation that low activation energy of N2 correlates with strong adsorption of intermediates, which blocks adsorption sites and hinders NH3 synthesis. Heterogeneous catalysts that allow facile activation of N2 and weak binding of N atoms would exhibit the optimal efficiency for these reactions. In this study, we employ first principles calculations and microkinetic modeling to study N2 activation and spillover on alloy surfaces. We demonstrate that incorporating single-atom alloy sites allows breaking scaling relations and fosters N spillover. This could lead to the development of new catalysts with enhanced activity due to the low N2 activation energy barrier relatively weakly bound N.