Analysis of solid products formed in atmospheric non-thermal carbon monoxide plasma

Thermodynamic analysis indicates that non-equilibrium plasma-chemistry of carbon monoxide can lead to the deposition of solid carbon oxides at low temperatures. Using a dielectric barrier discharge we are able to create deposits from CO readily at atmospheric pressure conditions. Deposition rates are on the order of 0.2 mg min(-1) at power of 12 W corresponding to about 1000kW-h kg(-1). Deposition rates increase with power although the most efficient deposition of carbon oxides is at lower power. Higher powers tend to increase the gas temperature and the carbon content of the films; this can be related to chemical kinetic considerations. Deposition rates are not significant functions of flow rate in the reactor, due to no significant depletion of the precursor over the range of flow rates tested. Gaseous products of the reactor were mainly unconverted CO precursor and trace amounts of CO2. The deposited material was characterized by elemental analysis, MALDI and ESI MS, FTIR and NMR. The material has chemical composition and characteristics similar to high pressure CO polymers and carbon suboxide polymers chemically formed from the monomer. Although some significant differences are observed including: a more disordered structure, slightly higher carbon incorporation and hydrogen incorporation, both latter conditions potentially resulting from the film reacting with water vapour after exposure to air.