Sputtered Cu-ZnO/γ-Al2O3 Bifunctional Catalyst with Ultra-Low Cu Content Boosting Dimethyl Ether Steam Reforming and Inhibiting Side Reactions

Dimethyl ether steam reforming (DME SR) is one of attractive technologies to online provide H2 for fuel cells in vehicles. Herein, we adopt a novel sputtering method to prepare a Cu-ZnO/γ-Al2O3 (CuZn–S) bifunctional catalyst with only 2.9 wt % Cu loading. The interaction between Cu and ZnO suppresses the thermal aggregation of Cu nanoparticles in DME SR. The Cu nanoparticles (methanol steam reforming sites) are highly and homogeneously dispersed and anchored on the external surface of γ-Al2O3 (DME hydrolysis sites). It significantly improves the utilization efficiency of the Cu species and the mass transfer, thereby achieving high catalytic performance for DME SR. Its reaction rate per unit mass of Cu is 50 times to that of the CuZnAlO/γ-Al2O3 catalyst at 300 °C. In addition, this unique structure inhibits the side reactions of methanol direct decomposition and reverse water gas shift to suppress CO production.