Predicting a Key Catalyst-Performance Descriptor for Supported Metal Nanoparticles: Metal Chemical Potential

The chemical potential of metal atoms in supported nanoparticles provides a convenient descriptor of their performance as heterogeneous catalysts that captures the effects of particle size, support, and alloying. Based on microcalorimetric measurements, the chemical potential is shown to be predictable as a function of monometallic particle diameter and the adhesion energy of the particle to the support, and for oxide supports, this adhesion energy correlates predictably with metal oxophilicity. These correlations provide predictions of metal chemical potential that can enable catalyst design. They also suggest an improvement in the Gibbs–Thomson relation for free-standing nanoparticles, whether metals or molecular solids.