A New Dome-Shaped Window into Plasma Chemistry

Nonthermal plasma catalysis is a promising technology for electrifying chemical processes, but observing the molecular dance inside reactors has proven notoriously difficult. Researchers use a technique called DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) to analyse surface chemistry using infrared light. However, standard setups often suffer from unstable discharges and fail to mimic the chaotic environment of practical dielectric barrier discharge (DBD) systems.

To solve this, a team has engineered a novel 'dome-type' flow cell. This device creates a stable glow discharge that closely models the electric fields and flow dynamics of real-world reactors. It remains operational for over an hour, delivering high-fidelity signals essential for detailed analysis.

Testing this rig on CO2 methanation—turning carbon dioxide into methane using a nickel catalyst—revealed crucial insights. The data showed the reaction primarily follows the Langmuir-Hinshelwood mechanism, where reactants interact on the surface, rather than colliding directly from the gas phase. This clearer view allows for the rational optimisation of future catalyst designs.