ECLIPSE Computational and experimental approaches to understanding CO2 hydrogenation to higher hydrocarbons using non-thermal plasma

CO2 is a critical feedstock for our future decarbonized energy and chemical industries. Chemical conversion of CO2 into useful fuels and chemicals, even in the presence of catalyst materials that effectively accelerate chemical reactions, requires high temperatures and/or pressures to counteract its inherent stability. A promising alternative is to use nonthermal plasma together with catalysts to circumvent conventional heat management and pressure requirements. Nonthermal plasma is composed of highly energetic electrons that can interact with molecules and activate strong bonds in stable molecules such as CO2. Plasma-enhanced catalysis processes are complex and involve coupled interactions across states of matter and length scales that remain poorly understood. This project promotes the progress of science and advances the field by disentangling and generating fundamental insights into the plasma-gas, gas-solid, and plasma-solid interactions that determine process performance (i.e., the amounts and types of products generated from the amount of CO2 and H2 consumed). The insights from this work will be incorporated into coursework at the undergraduate and graduate levels at Penn State across three different departments. The PIs will also develop modules for computational and experimental outreach activities at the middle-school and college levels. This project aims to dissect the coupled plasma-catalyst-molecule interactions that underpin plasma-enhanced catalysis, focusing on CO2 hydrogenation over FeCo bimetallic catalysts using dielectric barrier discharge (DBD) packed bed reactors. The specific goals are to (1) elucidate the relationship between plasma characteristics and the configuration/composition of packed catalyst beds, (2) understand how plasma characteristics influence gas-phase radical reactions in empty reactors and in packed beds of oxides, and (3) clarify the nature of catalyst active sites and their role in plasma-catalyst synergy. The interdisciplinary approach combines experimental methods from plasma science and heterogeneous catalysis together with theory (ReaxFF and eReaxFF based atomistic-scale simulations) to decouple plasma-catalyst/solid-molecule interactions across length scales. This work will provide fundamental understanding of the plasma-catalyst, catalyst-plasma interactions crucial for observed synergies, with specific insights for CO2 hydrogenation that are generalizable to plasma-enhanced catalysis. If successful, this work will accelerate development of plasma-based technologies as an alternative to conventional thermal processes, uniquely suited for our future electrified power grid. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.