Effect of Metal Oxides (CeO, ZnO, TiO, and AlO) as the Support for Silver-Supported Catalysts on the Catalytic Oxidation of Diesel Particulate Matter.

This work presented the influence of metal oxides as the support for silver-supported catalysts on the catalytic oxidation of diesel particulate matter (DPM). The supports selected to be used in this work were CeO (reducible), ZnO (semiconductor), TiO (reducible and semiconductor), and AlO (acidic). The properties of the synthesized catalysts were investigated using XRD, TEM, H-TPR, and XPS techniques. The DPM oxidation activity was performed using the TGA method. Different states of silver (e.g., Ag° and Ag) were formed with different concentrations and affected the performance of the DPM oxidation. AgO and lattice oxygen, which were mainly generated by Ag/ZnO and Ag/CeO, were responsible for combusting the VOCs. The metallic silver (Ag°) formed primarily on Ag/AlO and Ag/TiO was the main component promoting soot combustion. Contact between the catalyst and DPM had a minor effect on VOC oxidation but significantly affected the soot oxidation activity.