Synthesis of PtSn₄ Intermetallic Nanodisks through a Galvanic Replacement Mechanism

Abstract

Intermetallic compounds with ordered crystal structures are attractive materials with extensive applications in many fields. PtSn 4 , the most Sn-rich Pt−Sn intermetallic compound discovered so far, has special physical and catalytical properties because of the "Sn−Pt−Sn" layered crystal structure. However, studies on the property of PtSn 4 have been limited to the single crystal due to the lack of success in preparing PtSn 4 nanomaterials. Here, starting from Sn nanoparticles, we demonstrated the preparation of monodisperse pure-phase PtSn 4 intermetallic nanodisks (PtSn 4 NDs) based on a galvanic replacement mechanism. The structure of the as-synthesized PtSn 4 NDs was carefully characterized and analyzed. A systematic study on the PtSn 4 formation mechanism and kinetics confirms that the galvanic replacement mechanism governs the formation of PtSn 4 NDs. In electrocatalytic furfural reduction, PtSn 4 NDs effectively suppress the major competitive hydrogen evolution reaction and show faradaic efficiency superior to Pt nanoparticles.

Galvanic Replacement Reaction: Enabling the Creation of Active Catalytic Structures

“…For example, only pure PtSn 4 was obtained based on GRR between Sn NPs and Pt 2+ precursors. PtSn, PtSn 2 , or other Pt rich intermetallic phases were not detected, despite of the value of beginning ratio of Pt/Sn . Pure Cu 6 Sn 5 phase and Cu 6 Sn 5 –Sn composites can be obtained based on reaction between Sn NPs and Cu 2+ ions .…”

“…PtSn, PtSn 2 , or other Pt rich intermetallic phases were not detected, despite of the value of beginning ratio of Pt/Sn. 54 Pure Cu 6 Sn 5 phase and Cu 6 Sn 5 −Sn composites can be obtained based on reaction between Sn NPs and Cu 2+ ions. 55 Pure NiSb hollow nanospheres can be prepared via GRR between Sb ions and interconnected Ni nanospheres of ∼80 nm at a temperature of 80 °C.…”

Recent progress in intermetallic nanocrystals for electrocatalysis: From binary to ternary to high‐entropy intermetallics

“… 39 Rhombohedral intermetallic Pd 8 Sb 3 hexagonal nanoplates with thickness of approximately 15.3 nm were prepared by reducing Pd(acac) 2 and SbCl 3 in benzyl alcohol via the solvothermal reaction, where polyvinyl pyrrolidone and NH 4 Br functioned as the shape‐directing agents (Figure 6D). 116 Interestingly, with the addition of W(CO) 6 while maintaining other reaction parameters unchanged, rhombohedral intermetallic Pd 20 Sb 7 rhombohedra were obtained, which were bounded by six rhombic faces that were obliquely intersected (Figure 6E). 118 Three types of L1 2 intermetallic Pt 3 Sn nanocubes with cubic, concave cubic (Figure 6F), and defect‐rich cubic shapes were synthesized via the solvothermal method 43 .…”

“…(D) STEM image of rhombohedral Pd 8 Sb 3 hexagonal nanoplates (left panel), and HAADF‐STEM image of a Pd 8 Sb 3 nanoplate (right panel). Reproduced with permission, 116 copyright 2022 Wiley‐VCH. (E) STEM image of rhombohedral Pd 20 Sb 7 rhombohedra (left panel), and HAADF‐STEM image of a Pd 20 Sb 7 rhombohedron (right panel).…”

“…113 Shape control has been achieved as well, with the assistant of capping agents that can selectively adsorb onto specific facets. So far, noble metal-based intermetallic nanocrystals with diverse shapes, including onedimensional (1D) nanorods/nanowires, 41,105,114,115 2D nanosheets/nanoplates, 25,39,44,49,116,117 and 3D polyhedra, 43,[118][119][120] have been prepared via wet-chemical synthesis. For example, L1 2 intermetallic Pt 3 Co hierarchical nanowires were prepared by reducing Pt(acac) 2 and Co(acac) 3 in oleylamine, where the formation of nanowires was ascribed to the usage of the cetyltrimethylammonium chloride (CTAC) shape-directing agent (Figure 6A).…”