A mixture of acetylene and hydrogen was reacted over HZSM-5 zeolite catalyst at 200 degreesC to produce ethylene. A stream containing ethylene and methane was then reacted over gallium-loaded and copper-loaded ZSM-5 to produce higher molecular weight hydrocarbons. The effect of co-feeding methanol or chloroform on the product distribution was also investigated. On the other hand, a mixture of acetylene and methane was reacted over metal-loaded ZSM-5 catalysts to produce higher molecular weight hydrocarbons with a carbon number of five and more. Palladium,, platinum, and nickel were among the transition metals tested. (C) 2003 Elsevier B.V. All rights reserved.