Synthesis of Chemically Ordered Pt3Fe/C Intermetallic Electrocatalysts for Oxygen Reduction Reaction with Enhanced Activity and Durability via a Removable Carbon Coating
Synthesis of Chemically Ordered Pt3Fe/C Intermetallic Electrocatalysts for Oxygen Reduction Reaction with Enhanced Activity and Durability via a Removable Carbon Coating
复制标题
DOI：
10.1021/acsami.7b07648
复制
发表时间：
2017-09-20
影响因子：
9.5
通讯作者：
Lee, Hyuck Mo
中科院分区：
文献类型：
--
作者：
Jung, Chanwon;Lee, Changsoo;Lee, Hyuck Mo
近年来，Pt 3 M（M = Fe、Ni、Co、Cu等）金属间化合物已被强调为氧还原反应（ORR）催化剂的有希望的候选物。通常，为了形成这些金属间化合物，合成合金相纳米颗粒，然后在高温下热处理。然而，纳米颗粒在热处理过程中容易团聚，导致电化学表面积（ECSA）降低。在本研究中，我们合成了Pt-Fe合金纳米粒子，并使用碳涂层来防止纳米粒子在热处理过程中团聚。结果表明，Pt_3Fe/C合金和金属间化合物Pt_3Fe/C的ECSA分别为37.6和33.3 m（2）g（pt）（-1）。Pt_3Fe/C具有优异的质量活性（0.454 A mg（pt）（-1））和稳定性，具有优异的抗纳米颗粒团聚和铁浸出的上级性能。密度泛函理论（DFT）计算表明，由于Pt 3Fe表面Fe原子的溶解势高于Pt-Fe合金表面，Pt 3Fe/C比Pt-Fe/C具有更好的稳定性。与商用Pt/C相比，用Pt 3Fe/C制备的单电池表现出更高的初始性能和更好的上级耐久性。我们认为，Pt 3 M化学有序的电催化剂是优秀的候选人，可能成为最活跃和持久的ORR催化剂。
Recently, Pt3M (M = Fe, Ni, Co, Cu, etc.) intermetallic compounds have been highlighted as promising candidates for oxygen reduction reaction (ORR) catalysts. In general, to form those intermetallic compounds, alloy phase nanoparticles are synthesized and then heat-treated at a high temperature. However, nanoparticles easily agglomerate during the heat treatment, resulting in a decrease in electrochemical surface area (ECSA). In this study, we synthesized Pt-Fe alloy nano particles and employed carbon coating to protect the nanoparticles from agglomeration during heat treatment. As a result, Pt3Fe L1(2) structure was obtained without agglomeration of the nanoparticles; the ECSA of Pt-Fe alloy and intermetallic Pt3Fe/C was 37.6 and 33.3 m(2) g(pt)(-1), respectively. Pt3Fe/C exhibited excellent mass activity (0.454 A mg(pt)(-1)) and stability with superior resistances to nanoparticle agglomeration and iron leaching. Density functional theory (DFT) calculation revealed that, owing to the higher dissolution potential of Fe atoms on the Pt3Fe surface than those on the Pt-Fe alloy, Pt3Fe/C had better stability than Pt-Fe/C. A single cell fabricated with Pt3Fe/C showed higher initial performance and superior durability, compared to that with commercial Pt/C. We suggest that Pt3M chemically ordered electrocatalysts are excellent candidates that may become the most active and durable ORR catalysts available.