Mo/HZSM-5 has been found active in Fischer-Tropsch synthesis (FTS). The catalysts were evaluated under various reaction conditions with low H-2/CO (molar ratio similar to 1.0) syngas typical of a synthesis gas derived from biomass gasification. Liquid hydrocarbons formed on the Mo/HZSM-5 were composed mainly of alkyl-substituted aromatics and lower branched and cyclized alkanes. Aliphatic hydrocarbons were detected only in trace amounts. Lower hydrocarbons produced included mainly methane, ethane, propane and iso-butane. Higher alcohols and carboxylic acids (C-1-C-6) were detected in the water phase liquids from FTS. It is supposed that the formation of hydrocarbons on Mo/zeolite is through bifunctional-zeolite acidity and molybdenum metal catalysis via mixed alcohols as the intermediates. Investigation on the effects of zeolite structure indicated that zeolite Y is also an excellent support for Mo in the FTS. (C) 2009 Elsevier B.V. All rights reserved.