Investigation on high catalytic activity mechanism of organopalladium catalyst on S-terminated GaAs(001)-(2×6) surface

Organopalladium molecules immobilized on the S-terminated GaAs(001), termed GaAs-S-{Pd}, have high catalytic activity and stability in the Heck reaction. It is thought that the presence of Ga-S bonds in the single atomic layer S-termination is essential for these catalytic properties despite the much higher thickness (~100 nm) of the organopalladium films. In this study, we demonstrate the retention of Ga-S bonds in ultra-thin GaAs-S-{Pd} by using reflection high-energy electron diffraction (RHEED) and scanning tunnelling microscopy (STM) to show that the organopalladium molecules are immobilized on an intact S-terminated GaAs(001)-(2times6) surface.