Methane Conversion to Higher Hydrocarbons by UV Irradiation

The potential for using UV photolysis to convert methane to higher hydrocarbons with high yields was demonstrated with a radio-frequency- (RF-) powered Kr/Ar discharge lamp (λ = 116.5 and 123.6 nm, flux = 3.3 × 1014 photons/s) at pressures of 47 and 93 kPa and at ambient temperature. The highest conversion was 39%. Photon yields for carbon−carbon bond formation were as high as 4.5. The main reaction products were hydrogen, ethane, propane, and n- and i-butane, but smaller amounts of ethylene and higher alkanes were also detected. The hydrocarbon products followed a Flory distribution.