Theory, Modeling and Simulation
Computational Insights into Catalytic Oxidation on Cobalt Oxide and the Metal-Support InteractionMarch 08, 2013
Perspective view of the most stable configuration of Pt8
Computational studies of catalysis by transition-metal oxides and the metal-support interaction are exciting yet challenging. Here we show several examples of how we understand the catalysis by transition metal oxides and how we use global minimization to approach the metal-support interaction. First, we discuss CO oxidation on Co3O4(110), motivated by recent experiments that Co3O4 nanorods with preferred (110) facets display a high CO oxidation activity even at –77 oC. Using the DFT+U method, we elucidated the catalytic mechanisms and found that the low-coordinate oxygen is responsible for the high reactivity. Second, we examined the interface between subnanometer gold clusters on Mg(OH)2, in an effort to understand the role of hydroxyl groups and found that the Au-OH bonding is ubiquous on OH-covered surfaces. Third, we studied subnanometer Pt clusters on TiO2(110) to address the structural transition of metal clusters with size on a support and found the 2D-to-3D transition at Pt5; in addition, we found that the structure of the metal cluster is a result of optimizing Pt-Pt, Pt-O, and Pt-Ti bonds. Looking into the future, we envision that a DFT-validated, force-field-based approach will be the key driving force towards revealing the metal-support interface, while the DFT+U method will be applied to catalysis by more complex transition metal oxides.