Diesel soot emissions adversely affect human health, environment,
vegetation, climate change, etc. pressurizing governments to have strict
emission standards. This project describes the catalytic control of
diesel soot emissions. The performance of perovskite is found most
promising over spinel, hydrotalcite, and metal oxides catalysts for soot
oxidation. LaCoO3 prepared by co-precipitation shows the best result
(oxidizing soot totally at 370 oC) than catalyst prepared by sol-gel and
solution combustion synthesis. Potash substituted catalyst is more
effective than silver substituted. The optimum K substituted catalyst is
found to be La0.9K0.1Co0.9Cu0.1O3. A novel finding of the project is
that La0.7K0.3ZnOy does not form perovskite structure and remain as
mixed metal oxides. This catalyst shows comparable activity to
perovskite and yields the following kinetic expression: Rate =
6.46x10^10.exp(-138.12kJ/RT)(m)gsoot/gcat.s