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AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Food, Pharmaceutical & Bioengineering Division
Poster session: Engineering Fundamentals in Life Science
Monday, November 6, 2023 - 3:30pm to 5:00pm
One strategy to activate ammonia at mild conditions over earth-abundant metal catalysts is by applying non-thermal plasma since the vibrationally excited species produced in non-thermal plasmas lower the temperature of NH3 cracking. However, modelling interfacial plasma-surface interaction is a multi-scale problem and building such simulation for a complex reaction mechanism over a large search space of catalyst materials is computational immense.
To solve the above challenge, it is important to identify the key descriptor that impacts the overall rates of ammonia cracking under non-thermal plasma conditions and apply such descriptor to screen the large search space of catalysts. Thus, we first built the microkinetic model for ammonia cracking over various metallic surfaces (e.g., Ni, Co, Ru, Fe). Our theoretical results indicate that plasma lowers the energetics of the first N-H bond cleavage in NH3 and improves the overall rates by creating vibrationally excited state. Then we performed the sensitivity analysis to identify the key descriptor of N2 dissociative desorption from surface N*. We then applied this descriptor to scan the catalyst materials and found that earth-abundant Ni-Co alloy showed satisfactory catalytic performance compared to that of earth-rare Ru. AI-predicted catalysts will be further validated by experiments using a dielectric-barrier discharge reactor. The integration of multi-scale modeling, machine learning algorithms and experiments will facilitate materials development in interfacial plasma-surface reaction rather than trial-and-error.