Morphology of active species of Ag/ZrO2 for low-temperature soot oxidation by oxygen

Abstract

The catalytic oxidation of carbon black, a model soot, over Ag/ZrO₂ was studied. Transmission electron microscopy observations revealed that Ag nanoparticles with sizes of 2–10 nm on the catalysts presented 3–10 wt% Ag loading. Temperature-programmed reaction and transient activity measurements of carbon black oxidation revealed that the oxidation rate also increased with an increasing number of Ag nanoparticles on the catalysts up to 5 wt% Ag loading. The catalytically active Ag species thus was concluded to be nanoparticles with sizes of 2–10 nm.