A crucial role of surface oxygen mobility on nanocrystalline Y2O3 support for oxidative steam reforming of ethanol to hydrogen over Ni/Y2O3 catalysts

Y2O3 nanocrystals hydrothermally synthesized at different pH are found to have different morphologies and crystal sizes. These Y2O3 nanocrystals have been investigated as supports of Ni-based catalysts in oxidative reforming reaction of ethanol. Result of H2-chemisorption shows that the particle size and dispersion of nickel on Y2O3 nanocrystals are not affected significantly by the crystal size of Y2O3. XPS and H2-TPR results show that no association between nickel and the support-Y2O3 has taken place and the reducibility of nickel is not affected by the crystal size of Y2O3. However, it is found that the surface oxygen mobility of Y2O3 nanocrystal increases with decreasing crystal size. The surface oxygen mobility is believed to play an important role in promoting the H2 production rate and selectivity of the Ni/Y2O3 catalyst over the oxidative steam reforming of ethanol.