Pathways of partial oxidation of dimethyl ether under cold plasma conditions have been studied by density functional theory method in this work. Total energies, energy barriers and reaction enthalpies at 0 K or 298.15 K have been calculated at GGA/PW91 /DNP level. The calculation shows that, with the presence Of O-2, the energy barrier of dimethyl ether conversion is reduced and the conversion from dimethyl ether to H-2 and CO is promoted under cold plasma conditions. The formation of syngas is through a multi-step pathway via the conversions of metboxymethyl radical (CH3OCH2.), formaldehyde, HCO center dot, CH3 center dot, CH3O center dot, while the recombination of H generates extra hydrogen. The formation and effect of dimethyl ether anions have been also investigated in this work. (c) 2007 Elsevier B.V. All rights reserved.