Construction of trace silver modified core@shell structured Pt-Ni nanoframe@CeO₂ for semihydrogenation of phenylacetylene

The Pt-Ni nanoframe catalysts have attracted great interest owing to their unique electronic structure and excellent catalytic performance. However, the stability of the tenuous edges of nanoframe-structures is dissatisfactory and their universal applications in catalytic market beyond electrocatalytic reactions are yet to be tapped and explored. Herein, we developed a new core@shell structured Pt-Ni nanoframe@CeO₂ (Pt-Ni NF@CeO₂) composite via etching the Ni from inhomogeneous Pt-Ni rhombic dodecahedra (Pt-Ni RD) by cerium(III) acetate hydrate (Ce(OAc)₃). In this path, Pt-Ni RD was used as self-sacrificial template, while the Ce(OAc)₃ serves as the provider of the Ce³⁺ source and OH⁻ for the formation of CeO₂ shell, etchant of Pt-Ni RD, and the surface modification agent. By this way, the etching of Pt-Ni RD and the formation of the CeO₂ shell are simultaneously proceeded to form the final Pt-Ni NF@CeO₂ in one step. The obtained Pt-Ni NF@CeO₂ exhibits strong interfacial charge transfer interaction between Pt-Ni NF core and CeO₂ shell even without reduction treatment, leading to enhanced catalytic activity in the hydrogenation of phenylacetylene. After introduction of trace silver, the Pt-Ni-Ag_4.9 NF@CeO₂ achieves remarkable catalytic performance for the selective conversion of phenylacetylene to styrene: high conversion (100%), styrene selectivity (86.5%), and good stability. It reveals that encapsulation noble metal nanoframes into metal oxide to form core@shell structured hybrids will indeed enhance their stability and catalytic properties. Particularly, this work expends the application of noble metal nanoframes materials to hydrogenation reactions.