Research

The Little Machine is currently used to study the role of species buried beneath the surface in catalytic surface reactions. For example, we have previously shown that H atoms adsorbed on a Ni surface do not hydrogenate ethylene to ethane. Rather, H atoms absorbed beneath the surface are the reactive species for hydrogenation. These bulk H atoms must be produced by either collision induced absorption or exposure to an atomic H beam. We are currently exploring whether modification of the Ni electronic structure by formation of a surface alloy with Au will result in unactivated dissociative absorption of molecular hydrogen, resulting in ready production of bulk H in an ultrahigh vacuum environment. The results of this investigation will reveal why the commercial hydrogenation catalyst, also a Ni surface alloy, is so very efficient at adding hydrogen across double bonds.

Key features

• Triply Differentially Pumped Molecular Beam Source.
• Molecular Beam Precisely Coupled to Ultra High Vacuum Scattering Chamber.
• Single Crystal Nickel (111).
• Rotatable Crystal Mount on Liquid N2 Cooled Manipulator.
• High Resolution Electron Energy Loss Spectrometer (HREELS)
• Residual Gas Analysis Mass Spectrometer Detector.
• Molecular Beam Equipped with Chopper Wheel for Time of Flight Analysis.
• Auger Electron Spectrometer (AES).
• Hydrogen atom beam.
• Gold atom source.