Study on the Adsorption and Activation Behaviours of Carbon Dioxide over Copper Cluster (Cu₄) and Alumina-Supported Copper Catalyst (Cu₄/Al₂O₃) by means of Density Functional Theory

Figure 6

The optimized structure of the d1 (a, c) and d2 (b, d) adsorption configurations of CO₂ on Cu₄ and Cu₄/Al₂O₃ (red, oxygen atom; violet, alumina atoms; brown, copper atoms). Key distances are given in Å, and angles are in degree.

(a)

(b)

(c)

(d)