Preparation of Cerium-Bismuth Oxide Catalysts for Diesel Soot Oxidation Including Evaluation of an Automated...

Cerium-bismuth oxides have emerged as promising candidates for Diesel soot oxidation. The catalysts are synthesized via automated co-precipitation methods. T₅₀ values, where 50 % of soot is oxidized, and the dynamic oxygen storage capacity (OSC_dyn ) are used to compare the catalytic activity. The activity is measured by thermogravimetric methods. The synthesized catalysts are characterized through powder X-ray diffraction (PXRD), Raman spectroscopy, and specific surface area (S_BET ) measurements. This work investigates the influence of the contact mode between soot and catalyst. The literature-known manual contact modes "loose", "tight", and "wet" are compared with our developed automated contact mode, using a dual asymmetric centrifuge. The rotation speed rs and mixing time t_M have been varied independently. Both factors influence the T₅₀ value. A continuous transition from loose to tight contact mode with increasing rotation speed rs can be shown. Furthermore, the automated contact mode shows better reproducibility behavior compared to manual contact modes.