Abstract: Cu/ZnO/Al₂O₃ ultrafine particle catalysts were prepared by various methods such as coprecipitation, supercritical fluid drying, vacuum freezing drying and organic cpmplex decomposing.The characterization of catalysts and performance of methanol synthesis from CO₂+H₂ over these catalysts at 2 MPa were also investigated.The results indicate that the catalyst prepared by oxalate gel-coprecipitation shows higher BETarea and smaller particle size than by the other methods, and it also shows the highest activity and methanol selectivity.Methanol is directly formed from CO₂ other than from CO via reverse water gas shift reaction.Thermodynamic equilibrium was reached at about 230℃, 2 MPa and GHSVof 3600 h^-1。

Key words: Ultrafine particle, Methanol synthesis, Cu/ZnO/Al₂O₃ catalyst, CO²⁺H₂