Preparation of mesoporous CuO/γ-Al₂O₃ for one-step synthesis of dimethyl ether from syngas

Solvent evaporation self-assembly method was adopted to synthesize CuO/γ-Al₂O₃ composite catalysts with mesoporous structure using F₁₂₇ as template, aluminum isopropoxide and copper nitrate as precursor. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), H₂ temperature program reduction (H₂-TPR), nitrogen adsorption-desorption and transmission electron microscope (TEM) were used to characterize the properties of the catalysts. The results show that ordered and uniform mesoporous structure as well as large specific surface area were discovered in catalysts with different copper contents. In the syngas to dimethyl ether (DME) reaction, the highest conversion of CO reached 68.8% and the selectivity of DME achieved 59.0% under space velocity of 1 500 h^-1, 320 ℃ and 5 MPa. The conversion of CO decreased from 68.8% to 59.5% after 50 h on stream, and the selectivity of DME kept constant. The partial loss of activity was due to the aggregation of copper on this catalyst.