Carbon-Supported High-Entropy Oxide Nanoparticles as Stable Electrocatalysts for Oxygen Reduction Reactions
Carbon-Supported High-Entropy Oxide Nanoparticles as Stable Electrocatalysts for Oxygen Reduction Reactions
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DOI：
10.1002/adfm.202010561
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发表时间：
2021-03-19
影响因子：
19
通讯作者：
Hu, Liangbing
中科院分区：
文献类型：
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作者：
Li, Tangyuan;Yao, Yonggang;Hu, Liangbing
碳质载体上的纳米粒子是一种很有前途的电催化剂。然而，在长期操作期间实现电催化剂的良好稳定性，同时保持高活性仍然是一个巨大的挑战。本文报道了一种具有高熵氧化物（HEO）纳米颗粒均匀分散在商业炭黑上的高稳定性和活性的电催化剂，其通过快速高温加热（约1 s，1400 K）合成。值得注意的是，具有创纪录高熵的HEO纳米颗粒由十种金属元素组成（即，Hf、Zr、La、V、Ce、Ti、Nd、Gd、Y和Pd）。快速高温合成可以调整结构稳定性并避免纳米颗粒分离或团聚。同时，高熵设计可以提高化学稳定性，防止元素偏析。使用氧还原反应作为模型，10元HEO表现出良好的活性并大大增强了稳定性（即，92%和86%的保留率）与商业Pd/C电催化剂（即，12小时后保留率为76%）。这种上级性能归因于高熵组成设计和合成方法，其提供了熵稳定效应和纳米颗粒与碳基底之间的强界面结合。该方法有望为合成具有良好稳定性和高活性的碳载高熵电催化剂提供一条可行的途径。
Nanoparticles supported on carbonaceous substrates are promising electrocatalysts. However, achieving good stability for the electrocatalysts during long-term operations while maintaining high activity remains a grand challenge. Herein, a highly stable and active electrocatalyst featuring high-entropy oxide (HEO) nanoparticles uniformly dispersed on commercial carbon black is reported, which is synthesized via rapid high-temperature heating (approximate to 1 s, 1400 K). Notably, the HEO nanoparticles with a record-high entropy are composed of ten metal elements (i.e., Hf, Zr, La, V, Ce, Ti, Nd, Gd, Y, and Pd). The rapid high-temperature synthesis can tailor structural stability and avoid nanoparticle detachment or agglomeration. Meanwhile, the high-entropy design can enhance chemical stability to prevent elemental segregation. Using oxygen reduction reaction as a model, the 10-element HEO exhibits good activity and greatly enhances stability (i.e., 92% and 86% retention after 12 and 100 h, respectively) compared to the commercial Pd/C electrocatalyst (i.e., 76% retention after 12 h). This superior performance is attributed to the high-entropy compositional design and synthetic approach, which offers an entropy stabilization effect and strong interfacial bonding between the nanoparticles and carbon substrate. The approach promises a viable route toward synthesizing carbon-supported high-entropy electrocatalysts with good stability and high activity for various applications.