Fractional-order desorption of D 2 from a Pd(110) surface

The desorption of deuterium from the low temperature (α ₂) state on a Pd(110) surface was studied by TDS, LEED and ∆φ. Simultaneous measurements of the isothermal desorption of the α ₂ state, intensity of a half-order beam of the (1 × 2) phase and work function change show clearly that the desorption of this low temperature state is associated with the phase transition (1 × 2) to (2 × 1). This transition correlation with a work function change of ∼ 70 mV. The desorption follows nearly zero-order kinetics with an activation energy of ∼ 71 kJ mol ^-1. The desorption kinetics are thus closely analogous to those on Ni(110).