Soot oxidation performance of Cs-V-based non-noble catalyst used for diesel particulate filter and its regeneration performance by La doping

Abstract

The catalytic diesel particulate filter (CDPF) has consistently been a standard setup for diesel engines. This research introduces and enhances a non-noble metal catalyst, Cs-V, by doping with the rare-earth element La for the CDPF. The impact of La doping on the Cs-V-based soot oxidation catalyst was quantitatively studied using physical and chemical analysis, activity testing, and density functional theory (DFT) techniques. Findings indicated that introducing La into the Cs-V-based non-noble metal catalyst led to an increase in both the surface area and pore volume by 41 % and 18.4 %, respectively. The addition of La enhanced both the clustering and spatial distribution of catalyst particles, positively impacting absorption and catalytic activity. Doping with La significantly increased the chances of oxygen adsorption and dissociation activation in catalytic processes, enhancing the chance of soot-oxidation, lowering the activation energy to 62.1 kJ/mol, and decreasing T₁₀(the temperature at which the conversion rate of soot begins to reach 10 %), T₉₀(the temperature at which the conversion rate of soot reaches 90 %), and, T_m(the peak temperature at which the conversion rate of soot reaches) by 70.2 °C, 66.9 °C, and 69.1 °C respectively in contrast to their un-doped counterparts, while concurrently, La doping led to an average 4.5 % boost in the CDPF regeneration effectiveness. DFT simulation indicated that La doping can weaken the bonding between O atoms, lengthen the bond length between V atoms and solid O_asd within the crystal cell, shorten the bond length between V atoms and solid O_asd with C₄ molecules, increase the electronegativity of the configuration O_asd, and make the chemical bonds formed by V*-O* more inclined towards ionic bonds, these changes promote the desorption of -CO_x groups during soot-oxidation.