Preferential Growth of Pt Particles on Rutile TiO$_2$

Pt/TiO$_2$ is the prototype system exhibiting strong-metal- support-interaction phenomenon. The characterization of a real Pt/TiO$_2$ catalyst system through a combination of atomic resolution Z-contrast images and electron energy loss spectroscopy in the scanning transmission electron microscope has revelaed an unexpected result: Pt particles have a strong tendency to nucleate on the rutile phase of TiO$_2$ rather than anatase. In order to address the selective growth of Pt on rutile, Pt atom binding energies on stoichiometric and reduced TiO$_2$ surfaces and surface oxygen vacancy formation energies have been calculated using first principles density functional theory calculations for both rutile and anatase phases.