Compositional Effects of Ceria-supported Nickel–copper Catalyst on Its Reduction Behavior and Catalytic Performance for Ethanol Steam Reforming

Abstract

We investigated the effects of the Ni : Cu ratio and metal loading of a CeO2-supported bimetallic Ni–Cu catalyst on its reduction behavior and catalytic performance during steam reforming of ethanol for H2 production. Compared with monometallic Ni and Cu catalysts, both the NiO and CuO phases in the bimetallic catalysts were reduced at lower temperatures to form fine NiCu alloy crystallites. At a reaction temperature of 673 K, Ni/CeO2 exhibited a higher H2 yield than Cu/CeO2 but also produced a large quantity of CH4 and carbon deposits. The undesired byproducts were substantially inhibited by replacing a portion of the Ni with Cu. The highest H2 yield and an excellent carbon inhibition were achieved when the content of each metal was 5 wt%. Notably, a physical mixture of Ni/CeO2 and Cu/CeO2, each with the same metal contents, exhibited a lower H2 yield and heavy carbon deposition. This indicates that the higher reducibility and alloying in the bimetallic catalyst are key factors for synergistic improvements of the catalytic properties.