Accelerated sintering of PtRh/Al 2 O 3 catalysts in an oxygen periodic pulse flow

PtRh catalysts were prepared by coimpregnation, with chlorine-free precursors of a γ-alumina. They were sintered at 973 K under a continuous flow of O2 (1% in Ar or air) or of a flow of Ar into which pulses of O2 were injected periodically. Under the latter conditions the sintering was significantly accelerated, particularly for a certain value of the period of O2 pulses.