DFT STUDY OF CO2 ADSORPTION OF CumCon(m plus n=2-7) CLUSTERS

A theoretical study was carried out of CO2 adsorption on CumCon(2 <= m + n <= 7) clusters using density functional method. Generally CO2 are located at top or bridge sites, while CO2 of Cu2Co4CO2, Co6CO2 and Cu2Co5CO2 clusters are absorbed at hollow sites. Co3CO2 and CuCo2CO2 clusters are more stable than their neighbors, while Cu2CO2 and Cu6CO2 clusters display stronger chemical stability. After adsorption, CO2 is activated with the elongation of the C-O bond owing to electrons transfer from Cu-Co clusters to 2 pi(u) anti-bonding orbit of CO2. More charge transfer often corresponds to longer C-O bond and larger adsorption energy, and the chemical activity is stronger correspondingly. Magnetic and electronic properties are also discussed.