Pd-Ni catalyst over spherical nanostructured Y2O3 support for oxy-CO2 reforming of methane: Role of surface oxygen mobility

Various sizes of monodisperse spherical Y2O3 particles were synthesized using homogeneous precipitation method as support of Pd-Ni catalysts for oxy-CO2 reforming of methane reaction. Characterization results show that particle size and crystal size of Y2O3 particles decreases with decreasing pH of precursor solution from Y5 to Y3. TPR results of Y2O3 particles show that the intensity of reduction peaks increases from Y5 to Y3 while the position of those peaks shifts to lower temperature from Y5 to Y3, suggesting that the surface oxygen mobility of Y2O3 particles increases from Y5 to Y3 due to decrease in crystal size of Y2O3 particles. Catalytic activity results show that CH4 and CO2 conversions as well as H2 and CO production rates increase from Pd-Ni/Y5 catalyst to Pd-Ni/Y3 catalyst. In contrast, the H2/CO ratio and carbon deposition rate decreases from Pd-Ni/Y5 catalyst to Pd-Ni/Y3 catalyst. These results show that the highest surface oxygen mobility on Pd-Ni/Y3 catalyst plays important roles in high catalytic activity and suppression of carbon deposition on Pd-Ni/Y3 catalyst in oxy-CO2 reforming of methane reaction.