Nanoscale high-entropy alloy for electrocatalysis

• Published in: Matter Vol. 6; no. 6; pp. 1717 - 1751
• Main Authors: Han, Xiao, Wu, Geng, Zhao, Shuyan, Guo, Jingjing, Yan, Muyu, Hong, Xun, Wang, Dingsheng
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 07.06.2023
• ISSN: 2590-2385; 2590-2385
• DOI: 10.1016/j.matt.2023.03.034

High-entropy alloys (HEAs) are a new kind of alloy with five or more alloy elements at equal or near-equal ratios. The tunable multicomponent structure and potential novel properties of HEAs have attracted widespread attention. Benefiting from advances in synthesis technology, nanoscale HEAs were acquired successfully, the high specific surface area and quantum size effect of which further improved their capacity for catalysis. Nevertheless, the complex composition of elements makes it challenging to clarify the atomic structure of HEAs, and their catalytic studies are still in their infancy. A comprehensive review summarizing the current understanding of the structure of HEAs and their catalytic performance is urgently needed. This review first presents basic insights into HEAs, including concept definition, structural features, and progressive synthesis and characterization technologies. Then, the electrocatalytic performance of HEAs is discussed based on the structural diversity and synergistic role of each component element. Considering the limitation of trial-and-error methods in dealing with this complex system, high-throughput screening technologies are also introduced. This review aims to promote the understanding of HEAs and therefore achieve the design of high-efficiency catalysts relying on HEAs. High-entropy alloys (HEAs) represent a new paradigm in alloy design, with at least five elements incorporated in near-equal proportions, deviating from traditional alloying strategies. The incorporation of multiple elements offers HEAs with diverse tunability and potential for novel properties, making them a subject of widespread attention. Advances in synthesis techniques have enabled the preparation of nanoscale HEAs, which possess a high specific surface area and quantum size effect, further enhancing their catalytic potential. However, the complexity of the elemental composition in HEAs has hindered the full understanding of their structure. Despite this challenge, recent research efforts have yielded inspiring results in recognizing the structure of HEAs. Additionally, advanced synthetic strategies for nanoscale HEAs have been explored, facilitating significant progress in high-throughput screening and electrochemical applications related to their constituent elements. This review provides a comprehensive summary of the current understanding of the structure of HEAs and corresponding characterization methods, as well as the recent advances in the preparation, high-throughput screening, and electrochemical applications of HEAs. The advent of high-entropy alloys (HEAs) has introduced a new avenue for alloy design. Considerable headway is presently being achieved in the synthesis, characterization, and high-throughput screening of nanoscale HEAs. The highly tunable structure of nanoscale HEAs has made them a top contender for electrocatalytic applications, although further exploration of their structure-function relationship is necessary. This review provides an overview of the latest advancements in the understanding of nanoscale HEAs and their electrocatalytic efficacy.