Exploring Pretreatment-Morphology Relationships: Ab Initio Wulff Construction for RuO2 Nanoparticles under Oxidising Conditions

We present a DFT-based Wulff construction of the equilibrium shape of RuO2 particles in an oxygen environment. The obtained intricate variations in the crystal habit with the oxygen chemical potential allow for a detailed discussion of the dependence on the oxidising pretreatment used in recent powder catalyst studies. The analysis specifically indicates an incomplete particle shape equilibration in previously used low-temperature calcination. Equilibrated particles could be active CO oxidation catalysts with long-term stability in oxidising feed and then represent an interesting alternative to the previously suggested core-shell concept.