Evaluation of perovskite catalysts prepared by flame spray pyrolysis for three-way catalyst activity under simulated gasoline exhaust feeds

摘要

We have used liquid-feed Flame Spray Pyrolysis (FSP) to prepare a series of high surface area, nanocrystalline perovskites of general formula AA'BB'O-3 (A= La, A'= Ca, Sr, Y, Ce; B= B'= Mn, Fe, Co, Ni). Use of the FSP method has allowed the systematic investigation of changing both A site dopant and B site cation while maintaining high surface areas. The resulting perovskites have been evaluated for their CO, HC and NO (threeway catalyst (TWC)) activity under simulated gasoline exhaust feeds, their oxygen storage properties and their stability to high temperature redox conditions. The activity of the perovskites has been compared to a low loaded commercial PdRh TWC and were found to be significantly poorer after mild calcination and very significantly deactivated after high temperature hydrothermal redox ageing.