Nanoporous PdCr alloys as highly active electrocatalysts for oxygen reduction reaction.
Nanoporous PdCr alloys as highly active electrocatalysts for oxygen reduction reaction.
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DOI：
10.1039/c5cp07184d
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发表时间：
2016-01
期刊：
影响因子：
--
通讯作者：
Huimei Duan;Caixia Xu
中科院分区：
文献类型：
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作者：
Huimei Duan;Caixia Xu
采用一种简便的去合金化方法制备了韧带尺寸均匀、晶粒尺寸可控的纳米多孔PdCr合金。的结构表征方法表明，NP-PdCr合金是由一个纳米级的互连网络骨架和中空通道在所有三个维度上延伸。电催化性能测试结果表明，与NP-Pd 67 Cr 33、NP-Pd和商业Pt/C催化剂相比，NP-Pd 75 Cr25合金具有上级的比活性和质量活性以及更高的催化稳定性。X射线光电子能谱（XPS）和密度泛函理论（DFT）计算均表明，Pd与Cr（25at%）合金化使Pd的d带中心下移，从而削弱了Pd-O键，提高了ORR性能。NP-PdCr合金具有上级的整体ORR性能、独特的结构稳定性和易于制备等优点，有望作为燃料电池相关技术的阴极电催化剂应用。
A simple and convenient dealloying method is used to prepare nanoporous (NP) PdCr alloys with uniform ligament dimensions and controllable bimetallic ratio. The structural characterization methods demonstrate that the NP-PdCr alloy is comprised of a nanoscaled interconnected network skeleton and hollow channels extending in all three dimensions. Electrocatalytic measurements indicated that the as-made NP-Pd75Cr25 alloy exhibits superior specific and mass activities as well as higher catalytic stability toward oxygen reduction reaction compared with NP-Pd67Cr33, NP-Pd, and commercial Pt/C catalysts. X-ray photoelectron spectroscopy and density functional theory calculations both demonstrate that the weakened Pd-O bond and improved ORR performances depend on the downshifted d-band center of Pd due to the alloying of Pd with Cr (25 at%). It is expected that the as-made NP-PdCr alloy has prospective application as a cathode electrocatalyst in fuel-cell-related technologies with the advantages of superior overall ORR performances, unique structural stability, and easy preparation.