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

摘要

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 H-2 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 H-2 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 H-2 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 H-2 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.