IRRADIATION OF THE CARBON DIOXIDE-METHANE SYSTEM: THE FORMATION OF FORMALDEHYDE

摘要

Carbon dioxide containing 1000 VPM of methane-14C has been irradiated with 4 MeV electrons, and the yield of formaldehyde-14C determined by liquid scintillation counting of the dimedone derivative. Temperatures were varied from 25 to 400 C, and some experiments were performed with unlabelled methane and the products analysed for methanol. Initial G values for formaldehyde were in the range 1-6 molecules/100 eV. Addition of 1% CO reduced G(CH20). Equilibrium CH2O concentrations at high doses were about 2 VPM. No methanol was detected. Consideration of mechanisms involving CH3 and CH2 radicals indicate that reactions of the latter are largely responsible for CH20 formation.