Enhanced Catalytic Performance of Manganese and Cobalt Co-doped CeO2 Catalysts for Diesel Soot Oxidation

Nanosized manganese and cobalt codoped ceria (Ce0.8Mn0.1 Co0.1O2-delta ) solid solutions have been prepared through simple coprecipitation method to study the effect of Mn and Co bidopants towards diesel soot oxidation. Pure ceria (CeO2), manganese doped ceria (Ce0.8Mn0.2O2-delta), and cobalt doped ceria (Ce0.8Co0.2O2-delta) solid solutions have also been prepared for comparison. XRD results revealed the formation of solid solutions in doped samples. XPS results confirmed the presence of more Ce3+ ions and surface adsorbed oxygen in codoped ceria. H-2-TPR study disclosed that the codoping of ceria exceptionally improves the redox behaviour of CeO2. The catalytic activity results demonstrate that Ce0.8Mn0.1Co0.1O2-delta shows much better activity (T-50 similar to 636 K) while compared to pure CeO2 (T-50 similar to 874 K) in tight contact conditions. A larger surface area, facile redox behaviour, and high concentration of surface adsorbed oxygen species are proposed to be the crucial factors for the enhanced catalytic activity.