Mesoporous High-Entropy Alloy Films

• Published in: ACS nano Vol. 18; no. 40; pp. 27617 - 27629
• Main Authors: Fu, Lei, Nam, Ho Ngoc, Zhou, Jun, Kang, Yunqing, Wang, Kaiteng, Zhou, Zilin, Zhao, Yingji, Zhu, Liyang, Nandan, Ravi, Eguchi, Miharu, Phung, Quan Manh, Yokoshima, Tokihiko, Wu, Kai, Yamauchi, Yusuke
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 08.10.2024
• Subjects: soft template; high-entropy alloy; mesoporous film; electrodeposition; methanol oxidation reaction
• ISSN: 1936-0851; 1936-086X; 1936-086X
• DOI: 10.1021/acsnano.4c08929

High-entropy alloys (HEAs) are promising materials for electrochemical energy applications due to their excellent catalytic performance and durability. However, the controlled synthesis of HEAs with a well-defined structure and a uniform composition distribution remains a challenge. Herein, a soft template-assisted electrodeposition technique is used to fabricate a mesoporous HEA (m-HEA) film with a uniform composition distribution of Pt, Pd, Rh, Ru, and Cu, providing a suitable platform for investigating structure–performance relationships. Electrochemical deposition enables the uniform nucleation and grain growth of m-HEA, which can be deposited onto many conductive substrates. The m-HEA film exhibits an enhanced mass activity of 4.2 A mgPt –1 toward methanol oxidation reaction (MOR), which is 7.2-fold and 35-fold higher than a mesoporous Pt film and commercial Pt black, respectively. Experimental characterization indicates that structural defects and a low work function of the m-HEA film offer sufficient active sites and fast electron-transfer kinetics. Furthermore, theoretical calculations demonstrate that the variety of favorable adsorption sites on multimetallic elements of HEA reduces the barriers for dehydration pathways and *CO species removal, ensuring optimal performance for complex MOR reactions. This work provides an effective approach to designing a variety of HEA catalysts with well-controlled porous structures for targeted electrocatalytic applications.