PREPARATION, CHARACTERIZATION AND CATALYTIC ACTIVITY OF THE SELECTIVE CO OXIDATION USING LA_(0.5)CE_(0.5)CO_(1-X)CU_XO_(3-A) PEROVSKITE CATALYSTS

摘要

Proton-exchange membrane(PEM) fuel cell have many advantages such as almost no emission of pollutants, low operating temperature, long stack life. The ideal fuel for PEMFC is pure hydrogen, with less than 50ppm CO. In our study, Perovskite catalysts (La_(0.5)Ce_(0.5)Co_(1-x)Cu_xO_(3-α), x=0.1, 0.3, 0.5) were synthesized by coprecipitation method at pH 7 or pH 11 and its catalytic activity of selective CO oxidation was investigated. The characteristics of perovskite catalysts were analyzed by N_2 adsorption, X-ray diffraction (XRD), SEM, O_2-temperature programmed desorption(TPD). The influence of the change of the O_2 concentration for selective CO oxidation was studied, too. The pH value at a preparation step made effect on particle morphology. The smaller particle was obtained with a condition of pH 7. The better catalytic activity was observed using catalysts prepared at pH 7 than pH 11.