Pt₃Co@Pt Core@shell Nanoparticles as Efficient Oxygen Reduction Electrocatalysts in Direct Methanol Fuel Cell

Abstract

Core-shell structured bimetallic platinum-metal (PtÀ M) nanoparticles, as a new class of active and stable nanocatalysts, have shown many advantages in increasing the utilization of precious Pt and improving electrocatalytic performances. Here, a core-shell Pt 3 Co@Pt supported on porous graphitic carbon (denoted as Pt 3 Co@Pt/C) is synthesized via a simple thermal method, and further used as an efficient electrocatalyst for oxygen reduction reaction (ORR) in the direct methanol fuel cell. An atomic-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) measurement combining with line-profile analysis reveals that the average thickness of Pt-shell is around 0.4-0.6 nm, forming an ultrathin catalytic layer. Given its unique geometric and electronic structure, the as-prepared Pt 3 Co@Pt/C displays highly enhanced electrocatalytic ORR activity and stability, boosted anti-methanol poisoning ability with a high onset potential and an exceptional half-wave potential in 0.1 M HClO 4 solution. Impressively, its mass activity (0.71 mA mg Pt À 1) and specific activity (2.75 mA cm Pt À 2) for ORR are 3.7-and 8.1-fold higher than those of commercial Pt/C catalyst, respectively. The Pt 3 Co@Pt/C nanocatalysts show remarkable tolerance against methanol poisoning, evidenced by the in situ Fourier-transform infrared (FTIR) spectroscopy. This work points out a path for the design of high-performance nanocatalysts for accelerating the development of clean energy technologies involving ORR.

Enhanced Performance of Sn@Pt Core-Shell Nanocatalysts Supported on Two Different Carbon Structures for the Hydrogen Oxidation Reaction in Acid Media

“…Moreover, no noticeable shift in the position of the peaks between the monometallic and the core-shell nanocatalysts has been observed. Such characteristic suggests that no atoms of the Sn core have incorporated into the Pt shell contracting it and provoking the formation of alloyed phases, as has been reported elsewhere for some other core-shell nanostructures [35,36]. Additionally, the broadness of the reflections suggests the nanosized feature of the anode materials.…”

In Situ Formed “Sn1–XInX@In1–YSnYOZ” Core@Shell Nanoparticles as Electrocatalysts for CO2 Reduction to Formate

“…For instance, they maximize the exposition of the shell component to the electrolyte as has been used to increase utilization of precious metals for ORR application. [ 58,59 ] They can also offer the possibility of tuning CO 2 R selectivity through cooperation between core and shell components as has been demonstrated for Ag@SnOx [ 60,61 ] and Cu@In(OH) 3 [ 57 ] catalysts for CO 2 RR.…”

Synergistic engineering of shell thickness and core ordering to boost the oxygen reduction performance

“…On the one hand, they are potential candidates for constructing promising IM@Pt nanocrystals. In fact, nanocrystals with thin Pt skin (one to three layers depending on substrates) on the L1 2 -Pt 3 Co 41,42 or Pt 3 Fe 43 core and the L1 0 -PtCo 25,44,45 or PtNi 46,47 core exhibits outstanding ORR performances. The combinations of thin the Pt skin and IM core with the L1 2 -PtFe 3 , 48 L1 1 -PtCu, 49–51 and L1 3 -Pt 3 Ni or Pt 3 Cu phase hold great application potential.…”