Reza Khoshbin - Reactor and Catalysis Research Center, Sahand University of Technology, Tabriz
Mohammad Haghighi

The effect of aging time on physicochemical and catalytic properties of CuO-ZnO-Al2O3/HZSM-5 nanocatalyst for direct conversion of syngas to DME has been investigated. Nanocatalyst synthesized using co-precipitation method in which the aging time was varied from 0-6 h. The physicochemical properties of nanocatalysts are studied by XRD, BET, FESEM and TPR-H2 techniques. The crystallite size of CuO-ZnO-Al2O3 has not been influenced significantly by increase of aging time, while relative crystallinity has been increased. FESEM analysis showed that, with the prolonging of aging time, the aggregation of CuO-ZnO-Al2O3 on HZSM-5 increased. It is shown that the active phase particle size is distributed between 25.0-127.14 nm with an average size of 48.36 nm in which 98% of the particles are in the range of below 100 nm. TPR-H2 profiles indicated that reducibility of nanocatalysts is enhanced with increasing of aging time. Catalytic performance was investigated at 200-300°C, 10-40 bar, GHSV=600 cm3.g/h and H2/CO=2. It was found that increase of aging time have great influence on the activity of nanocatalysts and 6 hour aged nanocatalyst showed highest catalytic activity. Furthermore, it was observed that the optimum operating condition for direct syngas to DME reaction is 275°C and 40 bar

ZnO-CuO-Al2O3, HZSM-5, Co-precipitation, Syngas, DME