Highly dispersed L10-PtZn intermetallic catalyst for efficient oxygen reduction

Abstract

Highly active and durable electrocatalysts with minimal Pt usage are desired for commercial fuel cell applications. Herein, we present a highly dispersed L1 0 -PtZn intermetallic catalyst for the oxygen reduction reaction (ORR), in which a Zn-rich metal-organic framework (MOF) is used as an in situ generated support to confine the growth of PtZn particles. Despite requiring high-temperature treatment, the intermetallic L1 0 -PtZn particles exhibit a small mean size of 3.95 nm, which confers the catalysts with high electrochemical active surface area (81.9 m 2 g Pt −1 ) and atomic utilization. The Pt electron structure and binding strength between Pt and oxygen intermediates are optimized through ligand effect and compressive strain. These advantages result in ORR mass activity and specific activity of 0.926 A mg Pt −1 and 1.13 mA cm −2, respectively, which are 5.4 and 4.0 times those of commercial Pt/C. The stable L1 0 structure provides the catalysts with superb durability; only a halfwave potential loss of 11 mV is observed after 30,000 cycles of accelerated stress tests, through which the structure evolves into a more stable PtZn-Pt coreshell structure. Therefore, the development of a Zn-based MOF as a catalyst support is demonstrated, providing a synergy strategy to prepare highly dispersed intermetallic alloys with high activity and durability.

Micropore‐Rich Carbon‐Confined Pt as the Phosphoric Acid Poisoning‐Resistant Electrocatalyst for Oxygen Reduction Reaction

“…In Figure 2c, we have noticed that the interplanar spacing of Pt (111) in Pt@MPC‐5 is 0.223 nm, smaller than that of pure Pt (0.226 nm). [ 21 ] Therefore, XRD (Figure 3c) was further conducted to get insight into the structure of Pt‐based NPs. As a result, significant peaks were observed at 25.4° and 31.1° in Pt@MPC‐5, corresponding to the intermetallic Pt 1 Zn 1 (PDF# 06‐0604).…”

The decisive role of adsorbed OH* in low‐potential CO electro‐oxidation on single‐atom catalytic sites

“…To answer the question, we deliberately synthesized Rh-N and Rh-C coordinated catalysts pyrolytically using a Zn-based organic framework as the carbon precursor and urea as the additional nitrogen source. 32,33 Precautions were exercised in the synthesis procedure to ensure the atomic dispersion of Rh-C and Rh-N sites. The Rh contents were systematically tuned (0.04−0.92 wt.%, Table S1), with N/C and C reference samples also studied for comparison.…”

Low-Loading Sub-3 nm PtCo Nanoparticles Supported on Co–N–C with Dual Effect for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells

“…Unfortunately, Pt suffers from the high cost and the limited resource . Thus, it is urgent to explore Pt-based catalysts with a lower loading and a more superior performance. , So far, many strategies have been developed to achieve the above goals, including support modulation, , alloying, − intermetallic compound fabrication, − and core–shell structure constructions. , …”