PrOx nanoparticles: Active and stable catalysts for soot combustion

Abstract

PrOx nanoparticles (10 nm; 81 m2/g) were synthesized and analysed as soot combustion catalyst in comparation with other reference materials including CeO2 nanoparticles and PrOx and CeO2 catalysts with three dimensionally ordered (3DOM) and without controlled structure. PrOx nanoparticles reached the highest activity; T50 decreases from 603 °C (uncatalysed combustion) to 494 °C. This high activity can be attributed to the high surface area/low crystal size, which enhances the soot catalyst contact, and to the improved reducibility. PrOx nanoparticles kept high activity (T50 = 520 °C) after aging at 800 °C, being significantly more active than aged PrOx catalysts with 3DOM and uncontrolled structure and also significantly more active than all aged CeO2 catalysis which suffer almost total deactivation upon aging. In all cases, PrOx catalysts are more active than CeO2 counterpart materials with the same structure and thermal history, and this applies to nanoparticles, 3DOM and uncontrolled structures.