Pt–Ni Seed-Core-Frame Hierarchical Nanostructures and Their Conversion to Nanoframes for Enhanced Methanol Electro-Oxidation

Abstract

Pt–Ni nanostructures are a class of important electrocatalysts for polymer electrolyte membrane fuel cells. This work reports a systematic study on the reaction mechanism of the formation of Pt–Ni seed-core-frame nanostructures via the seeded co-reduction method involving the Pt seeds and selective co-reduced deposition of Pt and Ni. The resultant structure consists of a branched Pt ultrafine seed coated with a pure Ni as rhombic dodecahedral core and selective deposition of Pt on the edges of the cores. Both the type of Pt precursor and the precursor ratio of Pt/Ni are critical factors to form the resulting shape of the seeds and eventually the morphology of the nanostructures. These complex hierarchical structures can be further graved into hollow Pt–Ni alloy nanoframes using acetic acid etching method. The larger surface area and higher number of low coordinate sites of the nanoframes facilitate the electrocatalytic activity and stability of Pt–Ni alloy for methanol oxidation as compared to their solid counterparts. This study elucidates the structural and compositional evolution of the complex nanoarchitectures and their effects on the electrocatalytic properties of the nanostructures.

Electrochemical activity of Ni-montmorillonite/Vulcan XC-72R carbon black nano-catalyst for the oxidation of methanol in acidic medium

“…Therefore, it is For comparing the obtained results with the literature, a comparison table was added. Table 2 summarizes the comparison between the characteristics of the prepared modified carbon paste electrode and some previously modified electrodes [36][37][38][39]. As shown, the prepared modified electrode in this research has acceptable performance for methanol oxidation in acidic medium compared to other ones.…”

Noble Metal Based Alloy Nanoframes: Syntheses and Applications in Fuel Cells

“…Chen et al (2019) studied the reaction procedure of seeded co-reduction for the fabrication of PtNi seeded core frame structures. By controlling the shape of seeds, rhombic dodecahedra structures were obtained by depositing the Pt on their corners and edges.…”

Composition-Dependent Oxygen Reduction Reaction Activity of Pt-Surfaced PtNi Dodecahedral Nanoframes

“…To further improve the ORR catalytic performance of the PtNi nanoparticles, tailoring their architecture becomes inevitable . Throughout the recent years, a variety of PtNi nanostructures have been reported, such as branched particles, , double dumbell, core–shell, hyperbranched nanostructures, octahedron, ,, dodecahedron, icosahedron, hexapods, nanocages, octahedral nanoframes, dodecahedral nanoframes, ,,, and multiframes …”

“…Previously, Chen et al developed a thermal evolution method to synthesize Pt 3 Ni polyhedral nanoparticles and dodecahedral nanoframes, and their ORR activities show the following order: Pt/C < PtNi polyhedra/C ≪ Pt 3 Ni nanoframes . Chen et al also demonstrated that PtNi nanoframes exhibited an enhanced ethanol electro-oxidation activity and stability than the Pt–Ni seed-core-frame nanostructures …”

“…34 the ORR catalytic performance of the PtNi nanoparticles, tailoring their architecture becomes inevitable. 35 Throughout the recent years, a variety of PtNi nanostructures have been reported, such as branched particles, 36,37 double dumbell, 38 core−shell, 5 hyperbranched nanostructures, 39 octahedron, 9,10,40 dodecahedron, 8 icosahedron, 41 hexapods, 42 nanocages, 28 octahedral nanoframes, 43 dodecahedral nanoframes, 7,8,37,44 and multiframes. 45 Among these nanostructures, hollow, three-dimensional nanoframes represent a promising structural paradigm for the development of ORR catalysts.…”