Activation of n-butane with translational energy on Ir(110)–(1×2)

Abstract

The initial activation probability s 0 for reactive dissociation of n‐butane on Ir(110)–(1×2) exhibits at least two reaction channels. For one the direct collisional activation probability is at least 0.21 independent of incident kinetic energy, increasing to near 0.7 with decreasing surface temperature and kinetic energy of the incident beam of butane as a result of trapping of the species in the molecule–surface potential well. At kinetic energies above 120 kJ/mol the reaction probability again increases due to the onset of an activated route. Comparison to the results obtained with ethane suggests that energy transfer to the surface dissipates energy in the collision so that less energy is available to penetrate the longer range repulsive barrier in order to form carbon–metal and hydrogen–metal bonds.