(233f) Understanding Catalyst Nuclearity and Local Coordination at Interfaces to Control CO2 Hydrogenation
In the first we stabilized sub-nanometer Cu and Pd species at defect sites inside metal organic frameworks (MOFs) having either ZrO2 or ZnO2 nodes. This allowed us to modify the proportion of interfaces with higher control than in typical approach of varying the size of metal particles supported by bulk oxides. For the second system, we either stabilized single atoms of noble metals (e.g., Rh, Pt, and Ru) at the surface of bulk magnetite (Fe3O4) or, as an inverse approach, we deposited small FeO2 domains onto the Rh metal particles. Both strategies allowed us to maximize the binding coverage of active carbonaceous species while still retaining the ability of the catalysts to activate H2. During this work, we quantitatively show how the coverages of adsorbed species and the barriers for H addition and C-O bond cleavage are controlled by nuclearity of active phases and environment at interfaces. As a consequence, we report rational strategies for tuning the activity and selectivity of a variety of catalysts for CO2 hydrogenation to CO or methanol.