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

Core‐shell structured bimetallic platinum‐metal (Pt−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 Pt3Co@Pt supported on porous graphitic carbon (denoted as Pt3Co@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 Pt3Co@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 HClO4 solution. Impressively, its mass activity (0.71 mA mgPt−1) and specific activity (2.75 mA cmPt−2) for ORR are 3.7‐ and 8.1‐fold higher than those of commercial Pt/C catalyst, respectively. The Pt3Co@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. [ABSTRACT FROM AUTHOR]