Preparation of Cerium‐Bismuth Oxide Catalysts for Diesel Soot Oxidation Including Evaluation of an Automated Soot‐Catalyst Contact Mode

Cerium‐bismuth oxides have emerged as promising candidates for Diesel soot oxidation. The catalysts are synthesized via automated co‐precipitation methods. T(50) 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 T(50) 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.