“…Because the density of corner, edge, or surface Au atoms relative to the number of total Au atoms in a particle increases with decreasing particle size, coordinatively unsaturated Au atoms at the corner, at the edge, and at the particle surface have been proposed to constitute the active sites. 19,30,34,45,50,53 Indeed, the binding of CO and O 2 are demonstratively higher at the corner or edge sites than on the terrace or on the smooth surface. 19,30,45 Moreover, DFT calculations show that oxygen and carbon monoxide can only adsorb on gold atoms with a coordination number less than 8 at a certain condition.…”