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The effect of precursors, such as copper nitrate, acetate, and chloride, on the bifunctional CuÀZnO/γ-Al 2 O 3 catalysts was investigated for the direct dimethyl ether (DME) synthesis from syngas. The catalysts were characterized by measuring the reducibility and the surface area of metallic copper, together with their acidity. The well-dispersed copper particles with a high reducibility as well as a large amount of weak acidic sites on the bifunctional CuÀZnO/γ-Al 2 O 3 catalysts, prepared from a copper acetate precursor, are responsible for its high catalytic activity. The quantity of the acidic sites is a more crucial factor for obtaining a high DME yield than the surface area of metallic copper on the bifunctional catalyst.

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Fischer-Tropsch Synthesis (FTS) on Fe-Cu-K/ ZSM5 catalysts prepared by varying the amount of active components for a given amount of ZSM5 has been investigated to elucidate the effects of iron concentration. The catalysts were prepared by conventional wet impregnation method using ZSM5 and subsequently calcined at 500°C for 5 h. The different catalytic performance is verified by the variation of microporosity such as surface area and pore size distribution of Fe-Cu-K/ZSM5, acidity, reducibility of active phases and the presence of various crystalline phases like a-Fe 2 O 3 , metallic iron and iron carbide. The characterization results are analyzed along with catalytic performance to arrive at optimum amount of active components and to obtain maximum selectivity of FTS products with high conversion of CO during FTS reaction.