Production of Oxygenated Hydrocarbons in Ar Containing Microplasmas

Atmospheric pressure low-temperature plasmas are being investigated to convert CH₄ into value-added compounds. In the presence of O₂, oxygenated hydrocarbons, including alcohols and aldehydes, can be produced. Although the desire for high throughput to produce large quantities of product typically motivates use of large volume reactors, arrays of micro-plasmas may also provide large throughput while enabling more precise control of reaction pathways. For example, mixtures of methane with Ar can enhance up-conversion due to Penning reactions where Ar^* dissociates or ionizes molecular gases. In this work, the production of oxygenated hydrocarbons, including CH₃OH, C₂H₅OH, and CH₂O, is examined in a plasma formed in a microfluidic channel using results from the 0D plasma chemistry model GlobalKin. Mixtures Ar/CH₄/O₂ can be used to regulate production of pure hydrocarbon species such as CH₃, C₂H₆, and C₃H₈ as well as selectively controlling production of oxygenated hydrocarbon densities. The underlying reactions responsible for the changes in production of oxygenated hydrocarbons will be discussed.