Making gold less noble

Self-consistent density functional calculations for the adsorption of O and CO on flat and stepped Au(111) surfaces are used to investigate effects wh ich may increase the reactivity of Au. We find that the adsorption energy d oes not depend on the number of Au layers if there are more than two layers . Steps are found to bind considerably stronger than the (111) terraces, an d an expansive strain has the same effect. On this basis we suggest that th e unusually large catalytic activity of highly-dispersed Au particles may i n part be due to high step densities on the small particles and/or strain e ffects due to the mismatch at the Au-support interface.