STM Chamber

The current project underway in the STM chamber focuses on exploring metal/metal oxide interfaces, in particular the interface between Ag/Pd. Metals dispersed on a reactive metal-oxide have potential to effect selective catalysis through cooperative interactions between the co-existing metal and metal-oxide phases. Noble catalysts like Ag can potentially be combined with more reactive metals such as Pd that can act as a bifunctional catalyst for efficient conversion of alkanes into value added products. Ag is a well-known catalyst known to promote partial oxidation which is extensively used in epoxidation reactions while PdO favors complete oxidation of alkanes after initial cleavage of C-H bonds. Using model bimetallic Ag-Pd system, low temperature activation of alkanes can be achieved using PdO generating alkyl species which can then be partially oxidized with Ag to produce value added products.

This chamber is equipped with mass spectroscopy (MS), fourier transform infared spectroscopy (FTIR), and scanning tunneling microscopy (STM). STM provides valuable insights into the surface structure of our catalysts by imaging the surface via a single atom tip which is rastered across the surface of the film.

The STM images from left to right show a pure film, a thin Pd- film, and a thick Pd- film. STM is an incredibly powerful tool which allows us to actually see surface roughness as well as kinks in the surface and the surface structure.