Postplasma Catalytic Model for NO Production: Revealing the Underlying Mechanisms to Improve the Process Efficiency

Abstract

Plasma catalysis is emerging for plasma-assisted gas conversion processes. However, the underlying mechanisms of plasma catalysis are poorly understood. In this work, we present a 1D heterogeneous catalysis model with axial dispersion (i.e., accounting for back-mixing and molecular diffusion of fluid elements in the process stream in the axial direction), for plasma-catalytic NO production from N 2 /O 2 mixtures. We investigate the concentration and reaction rates of each species formed as a function of time and position across the catalyst, in order to determine the underlying mechanisms. To obtain insights into how the performance of the process can be further improved, we also study how changes in the postplasma gas flow composition entering the catalyst bed and in the operation conditions of the catalytic stage affect the performance of NO production.

Is a catalyst always beneficial in plasma catalysis? Insights from the many physical and chemical interactions

“…The same reaction setup for plasma-catalytic N2 oxidation was also studied by Eshtehardi et al [114], who constructed a one-dimensional model with axial dispersion, which could attain even better agreement with the experimental results. In addition, these authors studied the effect of the gas composition entering the catalyst-bed, as well as various operating parameters, to illustrate opportunities for improving the process performance [114].…”

“…As such, this is also the case for almost all models [72,73,102,106,107,112,113,115] discussed in section 5.1, with exception of ref. [114], which describes a model for post-plasma catalysis. To circumvent this issue, higher dimensional models are required.…”

Controlled synthesis of NO in an atmospheric pressure plasma by suppressing NO destruction channels by plasma catalysis

“…By combining NTP with heterogeneous catalysis, synergistic effects may lead to higher production at lower energy costs [16]. Patil et al found that the NO production changed with the type of catalyst when using metal oxides as catalysts in a packed-bed DBD [17] with larger surface areas leading to higher N x O y concentrations.…”

Electrochemical NO Generation: Past, Present, and Future

“…This control allows for better mechanistic insights to study NO-dependent signaling in vitro, which presents an opportunity to be used as a non-invasive technique to study neurological disorders and brain function. 9 Many methods of NO production have been developed, which include biological generation, 10 cryogenics, 11 plasma, 12 and organic NO donors -including NONOates (vide infra). 13 (Figure 2A) In a report by Knowles et.…”

“…disclosed a plasma-based method to generate NO, where N2 and O2 are combined using a Pt catalyst at low pressure. 12 Mowery et. al.…”