Abstract
DME synthesis catalysts were prepared by a conventional precipitation method. Nitrates of Cu, Zn and Al (molar ratio was 6:6:1) were precipitated by 0.5M and 1M of Na_2CO_3 solution using with an automatic micro pump and a chemical glass pipette, respectively. The first catalyst (CZAγAl_2O_3 (L)) prepared from the diluted precipitation agent gave a larger surface area, pore volume and smaller particle size of active Cu species compared to those of the last catalyst (CZA-γAl_2O_3 (P)). Two catalysts were evaluated under the same reaction conditions (H2:CO-1:1, GHSV-1000 ml/g・h, T-2600C, P-4 MPa) with a slurry bed reactor. The CZA-γAl_2O_3 (L) provided the highest catalytic activity of 76% CO conversion and 55% DME selectivity (in C-mol%) after 9h reaction. It is supposed that the diluted concentration of Na_2CO_3 precipitation agent caused a formation of the fine and uniform distribution of active metal species of DME direct synthesis catalyst.
