Synergistic effects of CeO<sub>2</sub>-supported bimetallic Ni–Cu, Co–Cu, and Ni–Fe catalysts on steam reforming of ethanol

Abstract

The synergistic effects of CeO2-supported bimetallic Ni–Cu, Co–Cu, and Ni–Fe catalysts on the reduction properties, crystal structure, and catalytic performance during steam reforming of ethanol were investigated. Both metals in the bimetallic catalysts were reduced at lower temperatures than were the metals in the associated monometallic catalysts, and they formed alloy crystallites. It was confirmed from activity tests of the monometallic catalysts that Ni and Co were relatively active components and that Cu and Fe were less active. The combination of Ni and Co with Cu (Ni–Cu/CeO2 and Co–Cu/CeO2) resulted in increases in H2 and CO2 yields and inhibition of carbon deposition during reactions at 673 K. On the other hand, the incorporation of Ni with Fe (Ni–Fe/CeO2) showed a lower activity than did Ni/CeO2 at 673 K but exhibited a higher H2 yield and higher resistance to carbon deposition at 873 K, in which case NiFe alloys were formed. These results indicate the advantages of alloying a catalytically active metal with a less active metal during steam reforming of ethanol.