Boosting Bifunctional Oxygen Electrocatalysis with 3D Graphene Aerogel-Supported Ni/MnO Particles
Boosting Bifunctional Oxygen Electrocatalysis with 3D Graphene Aerogel-Supported Ni/MnO Particles
复制标题
用 3D 石墨烯气凝胶负载 Ni/MnO 颗粒促进双功能氧电催化
DOI：
10.1002/adma.201704609
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发表时间：
2018-02-01
影响因子：
29.4
通讯作者：
Tang, Yawen
中科院分区：
文献类型：
--
作者：
Fu, Gengtao;Yan, Xiaoxiao;Tang, Yawen
氧还原和析氧反应的电催化剂(ORR和OER)是金属-空气电池的关键，成本较高的铂和Ir/Ru基材料分别是ORR和OER的基准催化剂。本文首次将Ni与MnO物种结合，通过简单、可扩展的水凝胶路线制备了3D多孔石墨烯气凝胶负载的Ni/MnO(Ni-MnO/rGO气凝胶)双功能催化剂。合成策略依赖于氧化石墨烯(GO)交联的聚乙烯醇水凝胶的形成，这种水凝胶允许在热解后有效地捕获高活性的Ni/MnO颗粒。值得注意的是，所得的Ni-MnO/rGO气凝胶在碱性电解液中对ORR和OER都表现出了优异的双功能催化性能，可以与以前报道的双功能电催化剂相媲美。MnO主要贡献了ORR的高活性，而金属Ni则贡献了优异的OER活性。此外，这种双功能催化剂可以赋予国产锌空气电池比铂/碳+RuO2混合催化剂更好的功率密度、比容量和循环稳定性，证明了其在可充电金属-空气电池实际应用中的潜在可行性。
Electrocatalysts for oxygen-reduction and oxygen-evolution reactions (ORR and OER) are crucial for metal-air batteries, where more costly Pt- and Ir/Ru-based materials are the benchmark catalysts for ORR and OER, respectively. Herein, for the first time Ni is combined with MnO species, and a 3D porous graphene aerogel-supported Ni/MnO (Ni-MnO/rGO aerogel) bifunctional catalyst is prepared via a facile and scalable hydrogel route. The synthetic strategy depends on the formation of a graphene oxide (GO) crosslinked poly(vinyl alcohol) hydrogel that allows for the efficient capture of highly active Ni/MnO particles after pyrolysis. Remarkably, the resulting Ni-MnO/rGO aerogels exhibit superior bifunctional catalytic performance for both ORR and OER in an alkaline electrolyte, which can compete with the previously reported bifunctional electrocatalysts. The MnO mainly contributes to the high activity for the ORR, while metallic Ni is responsible for the excellent OER activity. Moreover, such bifunctional catalyst can endow the homemade Zn-air battery with better power density, specific capacity, and cycling stability than mixed Pt/C + RuO2 catalysts, demonstrating its potential feasibility in practical application of rechargeable metal-air batteries.