Catalytic removal of diesel soot particulates over K and Mg substituted La_(1-x)K_xCo_(1-y)Mg_yO3 perovskite oxides

摘要

K and Mg substituted perovskite catalysts La_(1-x)K_xCo_(1-y)Mg_yO3 (x = 0-0.4, y = 0-0.2) for soot combustion were prepared by citric acid complexation and characterized by XRD, FT-IR, SEM, TEM, EDS, H2-TPR, XPS and TG. Soot combustion was remarkably accelerated when K was introduced into LaCoO3. Then Mg was doped into the K substituted LaCoO3, soot combustion was further improved for the restrained growth of Co3O4 phase. K/Mg substitutions were responsible for enhancing activity of catalysts by improving reducibility as suggested by H2-TPR studies. Among all the catalysts, La_(0.6)K_(0.4)Co_(0.9)Mg_(0.1)O3 exhibited the highest activity.