Density functional study of CH3OH binding on small cationic CunAum+ (n + m ⩽ 5) clusters

Density functional theory calculations were performed to investigate the geometric and energetic properties of CunAum+–(CH3OH) and CunAum+–(CH3OH)2 clusters with n + m ⩽ 5. CH3OH prefers binding to Cu atom when both Cu and Au site co-exist in the mixed cluster. The alloying makes the Cu atoms more reactive towards CH3OH while the Au ones less reactive with n + m ⩽ 4. The red shift of the C–O frequency decreases as the number of methanol molecule increases. The atomic populations and the dissociation channels of the most stable CunAum+–(CH3OH) clusters have also been determined and discussed.