Activated carbon supported cuprous chloride, a rarely examined catalyst, was prepared and applied to the oxidative carbonylation of methanol. The catalyst was prepared by impregnation. Water insoluble cuprous chloride was dissolved in hydrochloric acid. The effects of the calcination temperature in preparing the catalysts were examined. The results showed that, as the temperature was increased, the major surface species in the catalyst shifted from CuCl32- to CuCl, then to Cu2Cl(OH)(3), and finally to Cu-0. Cuprous chloride appeared to be the active species for the production of dimethyl carbonate (DMC), and maximum amount of cuprous chloride in the catalyst occurred at a calcination temperature of 300 degrees C. (c) 2007 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.