Catalysis from First Principles: Towards Accounting for the Effects of Nanostructuring

The article deals with an issue of density-functional description of heterogeneous catalysts by nanoparticle models instead of still commonly employed slab models. Typically, active (metal) components are present in catalysts as nano-aggregates formed of many thousands atoms, remaining due to their size inaccessible even for modern first-principles computations. However, such species could be rather realistically represented by notably smaller computationally tractable model nanoparticles, whose surface sites only marginally change the reactivity with increasing particle size. Herein presented results are mainly related to methane dehydrogenation on Pt catalysts, methanol decomposition on Pd catalysts and the composition of active sites on Pt/ceria catalysts. They document the feasibility of taking nanostructuring effects into account in density-functional modeling (at least for transition metals) and, more importantly, demonstrate that ignoring the nanoeffects in these systems leads to misrepresentation of their catalytic properties.