Boosting Both Electrocatalytic Activity and Durability of Metal Aerogels via Intrinsic Hierarchical Porosity and Continuous Conductive Network Backbone Preservation

• Published in: Advanced energy materials 2021-02, Vol.11 (5), p.n/a
• Main Authors: Zheng, Yuanyuan, Yang, Jing, Lu, Xubing, Wang, Honglei, Dubale, Amare Aregahegn, Li, Yi, Jin, Zhao, Lou, Dongyang, Sethi, Navpreet Kaur, Ye, Yuhong, Zhou, Jing, Sun, Yujing, Zheng, Zhikun, Liu, Wei
• Format: Article
• Language: English
• Subjects: Aerogels; Carbon fibers; Cloth; Composite materials; Durability; Electrocatalysts; Electron transfer; fuel cells; Metal foams; methanol oxidation reaction; Ostwald ripening; Porosity; Porous materials
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.202002276

As an emerging class of highly and hierarchically porous materials with continuous conductive metal network backbones, metal aerogels have unleashed tremendous potential in various fields, especially in electrocatalysis. However, it remains a great challenge to maximize the utilization of the intrinsic structural advantages of metal aerogels due to the collapse of their structure during conventional electrode preparation caused by their brittle character. Herein, a general in situ silicone‐confined gelation strategy is developed to integrate metal aerogels (PtPd, PtAg, PdAg, and AuAg) into/onto macroporous skeletons (carbon cloth, carbon fiber foam, and nickel foam). The composite materials have good mechanical flexibility, and can be utilized directly under the condition of well‐preserved intrinsic structure of metal aerogels. This not only results in more efficient electron transfer and faster mass transport, but also eliminates Ostwald ripening and aggregation, leading to both remarkably enhanced activity and durability when compared to that made by conventional ink drop coating with collapsed and compressed structure. This work represents a significant breakthrough for metal aerogels, and provides inspiration for electrocatalyst design with both high activity and durability. Preserving the intrinsic structure of metal aerogels is extremely important to give them optimum activity in electrocatalysis and is realized by forming metal aerogels/macroporous skeleton composite via an in situ silicone‐confined gelation strategy. The well‐preserved hierarchically porous structure and continuous conductive network lead to faster mass transport, better electron conductivity, eliminate Ostwald ripening, and correspondingly remarkably boost electrocatalytic activity and durability.