Comparative study on properties of Pd-Ce-Zr catalysts synthesized by flame spray pyrolysis and solution combustion: Application for methane catalytic oxidation in electric field

摘要

A kind of Pd0.01Ce0.75Zr0.25O2 hollow nanospheres surrounded by small nanoparticles prepared by flame spray pyrolysis (FSP) method (Pd0.01Ce0.75Zr0.25O2-F) were used for methane oxidation in electric field. Compared with the samples synthesized by solution combustion method, more Pd active sites is exposed to Pd0.01Ce0.75Zr0.25O2-F catalyst surface and it shows higher redox performance. The methane conversion over Pd0.01Ce0.75Zr0.25O2-F is higher (T-50 = 320 degrees C in 5 mA electric field, GHSV = 50,000 mTg(-1) M-1), and the turnover frequency (TOF) is significantly increased (Delta TOF = 4.33 x 10(-4) x s(-1)) under the effect of electric field. There is a strong interaction between electric field and Ce-Zr metastable structure, which is due to the higher content of surface hydroxyl groups on Pd0.01Ce0.75Zr0.25O2-F surface.