Chemisorption of oxygen on gold surfaces

Transition of oxygen molecules on Au(110) from the physisorbed to chemisorbed state has been achieved by UV radiation at 28 K.1 This probably excites them from the triplet to the singlet 1Ag state in which all electrons are paired although the bond length is almost unchanged, the dissociation energy (396 kJ mol-1) is much decreased, and it appears that in this state it is more easily chemisorbed, probably without dissociation. Bombardment of this surface by 0+ ions led on TPD to recognition of a number of bound states.1 

Attempts to deposit oxygen atoms by the decomposition of nitrous oxide (N20) have not been successful.44 

There are several possible reasons why massive gold should chemisorb oxygen at high temperature, apart from effects due to impurities (1) electronic excitation of electrons from the 5d to the 6s level may occur, 

We may turn now to consider the results provided by the several sets of DFT calculations (see Appendix) that relate to massive gold surfaces.13-15,20 21,24 25 45 These treat in particular the likelihood of molecular adsorption, the activation energy for dissociative chemisorption and the strength of adsorption (binding energy) of oxygen atoms on Au(lll), Au(211) (a stepped surface), Au(221) (a kinked surface), as well 

Some further refinement can be added to this picture. Mulliken charge analysis has shown15 that gold atoms at kinks and steps have a smaller 

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