Dehydrogenation of ethane to ethylene was investigated in the presence of CO2 over Au catalyst supported on an Mn-doped ceria nanorod. The activity can be greatly enhanced by proper Mn doping. Mn was found to preferentially occupy defect sites or surface sites of ceria, resulting in the formation of extra oxide ions. Characterization results indicated that the reducible oxygen species related to ceria might play a vital role in the dehydrogenation. The addition of CO2 improved the stability of the catalysts remarkably, since CO2 can sustainably replenish the reducible oxygen species and eliminate the coke on the surface of the catalysts, which was proved by the H2-TPR and Raman analysis of spent catalysts. An ethane conversion of 17.4% with an ethylene selectivity of 97.5% can be obtained after 44 h of reaction.
