Exploring Morphology-Activity Relationships: Ab Initio Wulff Construction for RuO2 Nanoparticles under Oxidizing Conditions

TL;DR

This study uses density-functional theory to construct equilibrium shapes of RuO2 nanoparticles in oxygen, revealing how oxidizing conditions influence particle morphology and catalytic activity, with implications for catalyst stability and design.

Contribution

It introduces an ab initio Wulff construction method for RuO2 nanoparticles under oxidizing conditions, linking particle shape to catalytic activity and stability.

Findings

Particle shape varies with oxygen chemical potential.

Incomplete shape equilibration observed in low-temperature calcination.

Equilibrated particles may serve as stable CO oxidation catalysts.

Abstract

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