C2H2 semi-hydrogenation: Engineering the surface structure of Pt-based bimetallic catalysts to adjust catalytic performance

Abstract

Engineering the catalyst surface structure is an effective method to adjust the catalytic performance. This work designs a series of Pt-M (M = Au, Ag and Cu) catalysts with different atomic arrangements of surface structure, including the PtxMy IMCs, PtnL@PtxMy(n = 1–3), PtnL@M, and the subsurface Pt1L-M, aiming at illustrating the influence of surface structure on C2H4 activity and selectivity in C2H2 semi-hydrogenation using DFT calculations and microkinetic modeling. The results showed that adjusting surface structure effectively alters catalytic performance, which markedly depend on the ensemble size of active site and electronic properties. The d-band center of Pt-M catalysts is proposed as a good descriptor to efficiently evaluate C2H4 activity. Among the considered Pt-M catalysts, PtCu3 IMC is screened out to be the most suitable catalyst to present excellent C2H4 selectivity, better activity, and good stability under the optimized experimental conditions of 520 K and the pH2: pC2H2 ratio of 10: 1, which resulted from the smaller ensemble size of active site and moderate d-band center.