Synthesis and characterization of Cu-X/γ-Al2O3 catalyst by intermittent microwave irradiation for hydrogen generation from dimethyl ether steam reforming

A series of Cu-X/γ-Al2O3 (X = Fe, Co, Ni) catalysts were synthesized by a rapid intermittent microwave irradiation method for hydrogen generation from dimethyl ether steam reforming. Different parameters, such as the promoters of X (X = Fe, Co, Ni), microwave irradiation procedure and the ratio of metal to γ-Al2O3, were investigated. The results show that 2Cu-Fe/72γ-Al2O3 has the best performance, for which the agglomeration is prevented, CuO is well dispersed and the catalytic activity is improved. Promoter iron oxide in 2Cu-Fe/9γ-Al2O3 facilitates the watergas shift reaction, which lead to an increase in the conversion of CO to CO2 and hydrogen yield. Particularly, the 2Cu-Fe/72γ-Al2O3 catalyst, with the best molar ratio of metal to γ-Al2O3, shows a dimethyl ether conversion of >99% and a hydrogen yield of >98% and produces the lowest CO content of 1.4%, indicating that the synergism between dimethyl ether hydrolysis and methanol reforming requires an appropriate balance between the metallic Cu-Fe and the acid γ-Al2O3. The intermittent microwave irradiation technique provides a simple but effective method of the Cu-Fe/γ-Al2O3 synthesis with a good catalyst performance for the dimethyl ether steam reforming