An investigation on copper-loaded ceria-praseodymium catalysts for soot oxidation activity and its kinetics

Abstract

The Cu-loaded Ce-Pr catalyst series was successfully developed to study their performance on soot oxidation activity and its kinetic behavior. The doped samples showed a similar trend for cubic fluorite structure except for CuO, which possessed a monoclinic structure from the XRD analysis. Facet ratios [{100}/{111} and {110}/{111}] for the reactive planes were calculated from XRD spectra; the ratio was high for the 5 Cu-CP catalysts. The oxygen vacancy peaks were noticed from Raman spectra for the doped samples. 5 Cu-CP displayed the better catalytic activity of T<inf>50</inf> = 402 °C, which may be attributed to high reactive planes and better reducibility. The addition of Cu showed a slight enhancement in catalytic activity compared to CP and pure Ce. The kinetic triplets were evaluated: the activation energy (E<inf>a</inf>), pre-exponential factor (A), and the reaction model. Pure Ce displayed the lowest E<inf>a</inf> and A values, whereas pure Cu showed high E<inf>a</inf> and A values by all the methods. Graphical abstract: (Figure presented.) © The Author(s) under exclusive licence to Associação Brasileira de Engenharia Química 2023.