Structure–Activity Map of Ceria Nanoparticles, Nanocubes, and Mesoporous Architectures

Structure–activity mapping is central to the exploitation and optimization of nanomaterial catalysts in a variety of technologically important heterogeneous reactions, such as automotive catalysis and water gas shift reactions. Here, we present a catalytic activity map for nanoceria, calculated as a function of shape, size, architecture, and defect content, using atom-level models. The activity map reveals that as oxygen is gradually depleted from the nanoceria catalyst, so it becomes energetically more difficult to extract further oxygen. We propose that the oxygen storage capacity (OSC) of ceria corresponds to the level of oxygen depletion, where it becomes thermodynamically prohibitive to extract further oxygen from the material (positive free energy). Moreover, because the reaction enthalpy contributes to the free energy, we predict that the OSC is influenced by the particular reaction being performed. Specifically, the more negative the reaction enthalpy, the higher the potential OSC (notwithstanding...