Structural engineering of core–shell PtCu alloy catalysts for propane dehydrogenation: a DFT study

Abstract

Propane dehydrogenation (PDH) is an economically efficient and environmentally friendly industrial process for producing propylene. However, the understanding of the structure-performance relationship of PtCu bimetallic catalysts in PDH remains limited. In this work, we systematically investigated a series of PtCu bimetallic catalysts, including the Pt-skin Pt_xCu_y core–shell structures and Pt_xCu_y alloys, using first-principles calculations and ab initio molecular dynamics to assess their stability, activity, and selectivity. The results show that PtCu@Pt(111) and PtCu₃@Pt(111) exhibit improved stability and performance compared to Pt_xCu_y alloys, attributed to the electronic effect of Cu species and the compressive strain effect of the Pt-skin Pt_xCu_y structures. Furthermore, we clarified the electron density at the Pt–C interface and its influence on the electronic interactions within the Pt-adsorbate complex, revealing the pattern of catalytic activity changes. Notably, PtCu@Pt(111) demonstrated stronger resistance to carbon deposition compared to Pt(111), thereby suppressing hydrogenolysis side reactions. This work provides critical insights for the rational design of efficient Pt-based catalysts for PDH via a doping strategy.