Experimental Study on the Reaction of CCl₃F and CH₄ in a Dielectric Barrier Discharge Nonequilibrium Plasma Reactor

The reaction of CCl₃F (CFC-11) with CH₄ (in an argon bath gas) in a dielectric barrier discharge nonequilibrium plasma was examined. Oxygen and nitrogen were excluded from the feed stream and the reactions resulted in the production of fluorine-containing polymers, as well as a range of gaseous products including H₂, HCl, HF, C₂H₃F, C₂H₃Cl, C₂H₂ClF, CHCl₂F, CCl₂F₂, CH₃Cl, CH₂Cl₂, CHCl₃, and C₂Cl₄. The polymeric material synthesized during reaction is characterized as being non-cross-linked and random in nature, containing functional groups including CH₃, CH₂, CHCl, CHF, CF₂, and CF₃. The conversion level of CCl₃F increased from 37% to 63% as the input energy density increased from 3 to 13 kJ L^-1 (the applied voltage range was 14.1 to 15.2 kV, peak-peak). The electrical discharge was characterized and found to be a slight modification of filamentary discharge toward a diffuse discharge due to the presence of the relatively low concentration of CCl₃F and CH₄ (less than 2% each) in argon. A reaction mechanism is proposed describing the formation of gas phase, as well as polymeric products.