Steam reforming of dimethyl ether over composite catalysts of γ-Al2O3 and Cu-based spinel

In the system of γ-Al2O3 and Cu-Mn-Fe oxide, Mn/Fe ratio was optimized. Mn/Fe ratio exhibited influence on CO2 and CO selectivity. Mn-rich composite catalysts produced more CO than Fe-rich catalysts. The optimized atomic ratio of Cu/Mn/Fe was 2/1/3. DME conversion was not influenced by steam/DME ratio in the feed gas, while CO formation was suppressed with a rise in steam/DME ratio. Complete DME conversion was attained below 350 °C over the optimized composite catalyst. The optimal Al2O3/Cu-Mn-Fe weight ratio was between 1/2 and 1. High catalytic activity and thermal stability of the optimal composite was found by the time-on-steam test at as high as 400 °C for 100 h.