C2H2 semi-hydrogenation over Cu catalysts: Revealing the influence of Cu active site types on the catalytic performance

The type of active site is a critical factor to determine catalytic performance. Here, DFT calculations are employed to systematically investigate the influence of Cu active site type on C2H2 semihydrogenation. Generalized coordination number (GCN) from 2.5 to 7.5 is used as a descriptor to characterize the type of Cu active site, including the corner, defect, step, and terrace sites. Our results showed that GCN can differentiate the type of Cu active site. C2H2 semi-hydrogenation performance closely depends on the type of Cu active site and GCN. Among them, Cu defect site with the moderate GCN of 4.8 is screened out to exhibit the best catalytic performance, which significantly inhibits green oil formation, and presents excellent C2H4 activity and selectivity. This work provides a basis for rational design Cu catalysts with excellent performance by adjusting the type of active site and GCN in C2H2 semi-hydrogenation. (C) 2022 Elsevier Ltd. All rights reserved.