Insight into the effects of different ageing protocols on Rh/Al2O3 catalyst

Scheme of the Rh/Al2O3 catalysts aged under different protocols. For the N2 and the H2 aged samples, the Rh species mainly exist in large metallic Rh particles on the surface of Al2O3 in comparison to the fresh sample. For the air aged and cyclic aged samples, the RhOx particles with much larger size partially diffuse into the sub-layers of the Al2O3 supports and strongly interact with the support to form inactive Rh(AlO2)y.