Scalable and Controllable Synthesis of Pt‐Ni Bunched‐Nanocages Aerogels as Efficient Electrocatalysts for Oxygen Reduction Reaction

Abstract

Developing efficient and stable Pt‐based oxygen reduction reaction (ORR) electrocatalysts via both economical and controllable routes is critical for the practical application of electrochemical energy devices. Herein, a scalable, controllable, and general ambient‐O2‐involved aqueous‐solution cultivating strategy to prepare PtxMy (M = Ni, Fe, Co) bunched‐nanocages aerogels (BNCs AG) is demonstrated, based on a newly established high‐M‐to‐Pt‐precursor‐ratio‐and‐B‐incorporation‐facilitated M‐rich core and Pt‐rich shell hydrogel formation process. The Pt83Ni17 BNCs AG shows prominent ORR performance with a mass activity (MA) of 1.95 A mgPt−1 and specific activity of 3.55 mA cm−2, which are 8.9‐times and 9.6‐times that of Pt supported on carbon (Pt/C), respectively. Particularly, the Pt83Ni17 BNCs AG displays greatly enhanced durability (MA 82.6% retention) compared to Pt/C (MA 31.8% retention) after a 20 000‐cycles accelerated durability test. Systematic studies including density functional theory calculations uncover that the excellent activity is closely related to the optimized ligand and strain effects with the optimized Ni content in this aerogel; the outstanding durability is endowed by the lowered‐down Ni leaching with the optimized Pt/Ni ratio and the inhibited sintering due to its appropriate porosity. This work provides new perspectives on the development of electrocatalysts with both high performance and low cost.

Platinum–Nickel Alloy Nanowire Electrocatalysts Transform into Pt-Skin Beads-on-Nanowires Keeping Oxygen Reduction Reaction Activity During Potential Cycling

“…The formation of the Pt-skin on nanostructured Pt alloy catalysts is often mentioned as an effective way to prevent etching of alloying components including Ni − and provides higher catalytic performance by significantly lowering the binding energies of ORR intermediates (O, OH, and OOH). − Interestingly, during potential cycles, the structure of PtNi nanowires can be converted to a branched nanostructure involving the Ostwald ripening supported by the coexisting PtNi NPs . Similar branched or waved nanostructures have also been reported. ,− These results encourage us to synthesize PtNi NWs with different Ni contents and understand the relationship between the activity, durability, Ni contents, and structural changes via Ostwald ripening during potential cycles.…”

Modulating Electronic Metal‐Support Interactions to Boost Visible‐Light‐Driven Hydrolysis of Ammonia Borane: Nickel‐Platinum Nanoparticles Supported on Phosphorus‐Doped Titania

“…High‐resolution TEM (HRTEM) imaging revealed a lattice spacing of ca. 0.21 nm (Figure 1c, d), a value between those of the (111) planes of face‐centered cubic (fcc) Ni (0.20 nm) and Pt (0.23 nm), indicating a connection to the crystal planes of Ni−Pt alloys [39–41] . The average Ni 40 Pt 60 NP size was ca.…”

Modulating Electronic Metal‐Support Interactions to Boost Visible‐Light‐Driven Hydrolysis of Ammonia Borane: Nickel‐Platinum Nanoparticles Supported on Phosphorus‐Doped Titania

“…0.21 nm (Figure 1c, d), a value between those of the (111) planes of face-centered cubic (fcc) Ni (0.20 nm) and Pt (0.23 nm), indicating a connection to the crystal planes of NiÀ Pt alloys. [39][40][41] The average Ni 40 Pt 60 NP size was ca. 3.6 nm (Figure 1e).…”