Computer Controlled Temperature Programmed Desorption from Noble Metal Surfaces

Neel Lynn Giltinan with Gary Chottiner

Computer Controlled Temperature Programmed Desorption from Noble Metal Surfaces

[paper]

Temperature Programmed Desorption (TPD) provides insight that no other spectroscopy can give into the interactions between molecules and the surfaces on which these molecules are adsorbed.  TPD is performed in an ultrahigh vacuum (UHV) environment, ~ 10-10 Torr or 10-8 Pa, as this is necessary in order to prepare and maintain clean surfaces of materials such as gold and platinum, which will be studied in this project. Molecules such as hydroxylamine that are of interest for energy conversion and storage purposes will be adsorbed on a single crystal gold or platinum sample, and the sample will then be heated in a controlled fashion while a mass spectrometer monitors what comes off the surface as a function of temperature. A working TPD system will have to be assembled from existing components. Much of the effort will be initially be directed at developing software to interconnect and control the mass spectrometer, temperature sensor and heating power. This system will then be used to study the binding energies of simple molecules to a surface, as well as determine whether those molecules adsorb intact or in fragments.