Plasma Diagnostics of Dielectric Barrier Discharge Plasma Reactor on Catalysts Layer Using Optical Emission Spectroscopy.*

Since the mid-twentieth century, plasma physics researchers have introduced a number of technologies for achieving an efficient alternative-energy economy, namely Fusion including the works of a National Ignition facility and Tokamak reactors. With an alarmingly increasing concentration of greenhouse gases due to energy generation, Circular Carbon Economy was proposed as a methodology to reduce carbon emissions through Reducing, Reusing, Recycling, and Removing carbon-related by-products.

At The Pennsylvania State University, research on recycling carbon from carbon dioxide to hydrocarbons has been conducted with a Dielectric Barrier Discharge Plasma Reactor. Designed catalysts combined with plasma can achieve this conversion at low temperatures with low power consumption. Among the products (i.e., hydrocarbons and alcohol), paraffin can serve as an energy source and ethylene can be used for material production. Preliminary results have shown that catalysts and plasma conditions (i.e., applied voltage) can change the chemistry of plasma. The selectivity of certain products can be achieved through the altering of catalyst and plasma conditions. Optical emission spectroscopy is used to further analyze the interactions between the catalyst and plasma. 

A corona discharge plasma with a thin layer of catalyst on the side of the ground is set in a chamber designed for optical diagnostics. A Spectrometer is set to measure light intensity at different wavelengths. Distribution of light intensity can give insight into gas particles presenting in plasma. This allows for further analysis of chemical reactions within the reactor. Different catalysts would be applied for comparison of chemical reactions with plasma on different catalysts.