“Long” and “short” range electronic effects in the bonding of CO and H2 on CuNi alloy

The thermal desorption data of CO from the CuNi alloys cannot be explained by a local binding site picture alone. The CO activation energy of desorption from a Ni binding site decreases linearly with increased surface Cu concentration indicating the presence of a ligand (long range electronic) effect. In contrast, the H₂ activation energy of desorption is constant with alloy composition.