C2H2 selective hydrogenation over the single-atom Pt1/Cu catalysts: Unraveling the role of Pt active site type and its coordination environment in regulating catalytic performance

Abstract

To unravel the role of active site type and its coordination environment in regulating catalytic performance, C2H2 selective hydrogenation over a series of single-atom Pt1/Cu catalysts was fully investigated using DFT calculations and microkinetic modeling. Four types of Pt active site, including the defect, step, corner, and terrace sites with the generalized coordination number (GCN) from 2.5 to 7.5, are examined. Our results indicate that Pt1/Cu catalysts with four types of active sites favor gas phase C2H4 formation in C2H2 hydrogenation process. C2H4 activity has an inverted volcanic-type curve relationship with d-band center and GCN of Pt active site. For the polymerization process, the corner and terrace sites with larger GCN values could prevent green oil. The screened PtGCN3.0 catalyst with corner site exhibits better C2H4 selectivity and activity and prevents green oil. Hence, tuning the type and GCN value of Pt active site well regulate C2H4 activity and selectivity, as well as catalyst stability, which provide useful structure information to rationally design Pt-based catalysts in C2H2 selective hydrogenation.