Plasma-catalyst modeling for materials selection: challenges and opportunities in nitrogen oxidation

Reliable kinetic models are essential to rationalize observations and to guide the selection of appropriate plasma-catalyst combinations. Kinetic models coupling plasma- and heterogeneous-catalytic-chemistries, however, are primitive. Here, we combine reduced plasma chemistries and density functional theory parameterized surface reactions to model NO formation from N-2 oxidation, an alternative nitrogen fixation process. We first show plasma excited species can enhance turnover frequencies of both Pt and Au. The enhancing potential is a function of plasma species and their densities. We then compare NO production between plasma/Pt and plasma/Au with an integral reactor model and explore the dependence of NO production as a function of plasma conditions, reactor configurations and chemical compositions. Plasma/Pt generates more NO than plasma/Au under most thermal and plasma parametric conditions. Plasma/Au outperforms plasma/Pt under high plasma excitations at low temperatures. These results highlight that selection of plasma-catalyst combinations should consider the properties of plasmas, materials and the coupling of the two.

Automated summary

Reliable kinetic models are crucial for understanding observations and guiding the selection of suitable plasma-catalyst combinations. The study demonstrates that plasma excited species can enhance turnover frequencies of Pt and Au, with the enhancing potential being dependent on plasma species and densities. The comparison between plasma/Pt and plasma/Au reveals different NO production outcomes under various conditions.