Activity for Diesel Particulate Matter Oxidation of Silver Supported on Al2O3, TiO2, ZnO, and CeO2: The Effect of Oxygen Concentration

Particulate matter (PM) is a problem for human health the major producer of PM are diesel engines. The diesel particulate filters (DPFs) are used for the limitation of the PM. The DPF operation consists of two sequential functions: PM filtering and regeneration. One of the main contributing factors affecting the regeneration of DPF is the oxygen concentration in the exhaust gas. This study investigates the impact of different oxygen concentrations (99.99%, 10%, and 5%) on (PM) oxidation when using silver catalysts supported on CeO2, ZnO, TiO2, and Al2O3. The synthesized catalysts were characterized using XRD, SEM, SEMEDX, and H2-TPR techniques, and the PM oxidation activity was evaluated using TGA. The results demonstrated that different oxygen concentrations had little effect on light VOCs oxidation compared to no catalyst or the same catalyst. However, heavy VOCs and soot combustion, which require a higher oxygen concentration, significantly reduce combustion performance when the oxygen concentration decreases.