Oxidation treatment of diesel soot particulate on CexZr1−xO2

Catalytic oxidation of diesel soot particulate on CexZr1−xO2 catalysts was investigated. Results indicated that Ce/Zr ratios had a significant influence on the catalytic activities. Compared with the ignition temperature (Ti) of uncatalyzed soot combustion, Ti of Ce0.5Zr0.5O2 with the best catalytic behavior decreased by 80 °C. The reactant gas compositions (O2, H2O and NO) affected the catalytic activities too. O2-TPD, TG-DTA and XPS characterization results showed that CexZr1−xO2 released lattice oxygen continuously to promote the soot combustion even no gas oxygen occurred in the reaction atmosphere. The mechanisms of spill-over and reduction/oxidation functioned synergistically for soot catalytic combustion.