Oxidation of soot on iron oxide catalysts

Diesel particulate filters (DPF) represent a state-of-the-art technology for the removal of soot from diesel exhaust. However, the continuous regeneration of these filter systems remains a considerable challenge, as the trapped soot causes backpressure effects potentially decreasing the engine efficiency. While the so-called continuous regenerating trap (CRT) technique using nitrogen dioxide is already established for heavy duty vehicles, the catalytic soot oxidation by oxygen is considered to be a promising procedure for passenger cars, ships and work machines. Therefore, the present work addresses the rational development of a highly active iron oxide based catalyst for soot oxidation. The approach of this development process comprises three fundamental research methods, namely mechanistic and kinetic experiments, kinetic and fluid dynamic modelling and structure-activity relations of different types of iron oxides. A combination of this enables the synthesis of an advanced catalytic material, which is transferred to a real DPF system and tested under real diesel exhaust conditions.