Noble Metal-Free Nanoporous High-Entropy Alloys as Highly Efficient Electrocatalysts for Oxygen Evolution Reaction
Noble Metal-Free Nanoporous High-Entropy Alloys as Highly Efficient Electrocatalysts for Oxygen Evolution Reaction
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无贵金属纳米孔高熵合金作为析氧反应的高效电催化剂
DOI：
10.1021/acsmaterialslett.9b00414
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发表时间：
2019-11-01
影响因子：
11.4
通讯作者：
Sun, Shuhui
中科院分区：
文献类型：
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作者：
Qiu, Hua-Jun;Fang, Gang;Sun, Shuhui
开发用于析氧反应（OER）的高效催化剂是可充电金属 - 氧电池和水分解的关键步骤。通常，二元NiFe或三元NiCoFe纳米合金被用作OER催化剂。在此，将前驱体合金设计与化学蚀刻相结合，开发了一种简单的去合金化途径，以可控地将五种或更多种非贵金属纳入一种具有自然氧化表面的纳米结构合金中，即覆盖有高熵（氧）氢氧化物（HEO）的纳米多孔高熵合金（np - HEA）。研究发现，合金成分在提高OER活性方面起主导作用，其中np - AlNiCoFeX（X = Mo，Nb，Cr）组合表现出最高的活性。与三元和四元对应物相比，形成五元高熵合金还极大地提高了电化学循环稳定性。该结果表明在单相纳米结构中协同掺入五种或更多种金属元素的重要性，这提供了更多的结构和化学自由度以提高催化性能，克服了普通二元或三元合金的限制。多元过渡金属基np - HEA是一类用于各种重要反应的有前途的新型催化剂。
Developing highly efficient catalysts for oxygen evolution reactions (OER) is a key step for rechargeable metal-oxygen batteries and water splitting. Usually, binary NiFe or ternary NiCoFe nano-alloys are used as the-OER catalysts. Herein, combining the precursor alloy design with chemical etching, a simple dealloying route is developed to controllably incorporate five or more nonprecious metals into one nanostructured alloy with a naturally oxidized surface, that is, nanoporous high entropy alloys (np-HEAs) covered with high-entropy (oxy)hydroxides (HEOs). It is found that the alloy composition plays a dominant role in the OER activity enhancement with the np-AlNiCoFeX (X = Mo, Nb, Cr) combination showing the highest activity. Forming quinary HEAs also greatly enhances the electrochemical cycling stabilities compared with the ternary and quaternary counterparts. The result indicates the significance of synergistically incorporating five or more metal elements in one single-phase nanostructure, which provides more structural and chemical degrees of freedom to boost the catalytic performance, overcoming the restriction of normal binary or ternary alloys. Multinary transition metal-based np-HEA is a new class of promising catalyst for various important reactions.