A Strategy for Designing a Concave Pt–Ni Alloy through Controllable Chemical Etching

Abstract

This corrosion: Octahedral Pt-Ni alloy nanoparticles (NPs) are converted into concave Pt(3)Ni NPs by a coordination-assisted chemical-etching process. The corroded concave Pt-Ni NPs have a higher density of low-coordinate atoms in steps sites, a decisive property in heterogeneous catalysis.

Gold-promoted structurally ordered intermetallic palladium cobalt nanoparticles for the oxygen reduction reaction

“…Key strategies to reduce Pt contents involve alloying Pt with other transition metal [3][4][5][6][7][8] , de-alloying non-precious metal to obtain a Pt rich shell [9][10][11] and core-shell-structured nanoparticles [12][13][14][15] . These approaches, to some degree, increase Pt utilization, but cannot fully solve the problem of Pt dependence.…”

Understanding of the major reactions in solution synthesis of functional nanomaterials

“…For instance, our group presented a controllable "top-down" synthesis of concave Pt-Ni alloys which exhibited higher catalytic activity compared to the uncorroded alloys through a coordination assisted chemical-etching process (Fig. 23) [383]. Coordinating agent (dimethylglyoxime) with the presence of oxygen was used to control the chemical etching process at room temperature to synthesize a concave structure.…”

“…Driven by the difference in the chemical reactivity of two metallic species, the dealloying process has gained great success in constructing hollow [505], porous [506], concave [383,507] and frame structures [238] with fascinating geometrical beauty and interesting chemical and physical properties. The generated reactive sites such as interior vacancies and surface defects are strictly related to the dissolution of more active metals and rearrangement of the reserving residue.…”

New understanding of phase segregation of bimetallic nanoalloys

“…In 2012, Li's group reported that a concave octahedral Pt-Ni alloy with a Pt-segregated surface can be constructed using a controlled dealloying process [3]. This work has led to the effective design of nanosegregated Pt skins on Pt-based bimetallic nanoalloys using a simple wet-colloid method.…”

“…They showed that the surface steps in the Pt 3 Ni concave hexapod alloy formed in the initial stage of the synthesis were crucial in the segregation of an M-rich (M = Ni, Co, etc.) phase in the Pt-Ni alloy through step-induced deposition.…”