CO2 activation and conversion on Cu catalysts: Revealing the role of Cu surface defect types in tuning the activity and selectivity

Cu catalysts with different defect types are widely applied in CO2 activation and conversion, however, the underlying role of Cu surface defect types in tuning the activity and selectivity is still unclear due to the complexity of surface defect types. This work constructed a series of Cu catalysts including the perfect surface, as well as the point and line defect surfaces to reveal the role of Cu surface defect types on CO2 activation and conversion using theoretical calculations. The results show that Cu defect types can effectively tune the activity and selectivity of CO2 activation and conversion; the line defect Cu surfaces have higher CO2 activation activity than the point defect and perfect surfaces. Both the line defect Cu(1 1 1)LD and (5 1 1)LD surfaces are screened out to present the highest activity toward C1 and C2 species formation, respectively. Moreover, Cu surfaces with different defects present an inverted volcano-type curve between d-band center and CO2 activation activity, both Cu(1 1 1)LD and (5 1 1)LD with excellent activity are attributed to the moderate d-band center. Further, the generalized coordination number (GCN) of Cu surface is proposed and confirmed as an effective descriptor to predict the activity of CO2 activation on different Cu surfaces. The results can provide the valuable structural information for the design and prediction of Cu catalysts with excellent activity and selectivity in CO2 activation and conversion.