Soot-catalyst contact studies in combustion processes using nano-scaled ceria as test material

Combustion temperatures of particulate matter of Diesel automobile engines under lean conditions in laboratory experiments depend on a number of parameters: e.g. model gas composition and flow rate, catalyst composition and micro structure, soot/catalyst ratio as well as model soot type (composition, particle size and size distribution) and contact type. Especially the last two factors are often underestimated. In the literature most commonly Printex U and loose or tight contact are used. Here we report on the effect of these two parameters by varying the soot used and contact type and with nano-scaled ceria as catalyst due to its known Oxygen Storage Capacity (OSC). Apart from investigating the influence of these factors our second main objective was to find a preparation technique for the soot-catalyst contact, which fulfills the criteria of high reproducibility, high comparability to real conditions and facile automation. The last criterion is the basis for its use in high-throughput techniques (HTT) for parallelized discovery and optimization studies of new combustion catalysts.