Bai Jirong, Ge Wenzheng, Zhou Pin, Xu Peng, Wang Lingling, Zhang Jianping, Jiang Xiankai, Li Xi, Zhou Quanfa, Deng Yaoyao
Research Center of secondary Resources and Environment, School of Chemical Engineering and Materials, Changzhou Institute of Technology, Changzhou 213022, China; Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
Research Center of secondary Resources and Environment, School of Chemical Engineering and Materials, Changzhou Institute of Technology, Changzhou 213022, China.
J Colloid Interface Sci. 2022 Jun 15;616:433-439. doi: 10.1016/j.jcis.2022.02.080. Epub 2022 Feb 22.
Exploring highly-efficient noble-metal-free electrocatalysts for oxygen reduction reaction (ORR) is crucial for preparation of rechargeable metal-air batteries. Herein, FeNi-mIm (guest) was loaded on the surface of ZIF-8 (host) via a novel host-guest strategy, and the resulting ZIF-8@FeNi(mIm) precursors can be converted to FeNi SAs/NC catalysts with controllable structures. Robust metal-organic framework (MOF)-derived atomically dispersed Fe/Ni dual single atom electrocatalysts for ORR were developed, followed by pyrolysis of the precursors. Characterizations showed that the atomically-dispersed Fe/Ni active sites were uniformly embedded in the N-doped carbon framework. As a result, the ORR performance was obviously improved with lower half-wave potential (E = 0.91 V) in alkaline media. Such improvement is mainly attributed to the synergy of fully-exposed bimetallic single atom active sites caused by the interaction of Fe/Ni 3d orbitals. The lower adsorption energy of intermediate hydroxyl groups on the active sites and the smaller ORR energy barrier were calculated by the density functional theory. The novelty FeNi SAs/NC catalysts showed faster ORR dynamics in the rate-determining step of four-electron transfer. The synthesis strategy reported here provides an efficient approach to construct high performance dual single-atom catalysts with fully-exposed active sites on the surface.
探索用于氧还原反应（ORR）的高效无贵金属电催化剂对于可充电金属空气电池的制备至关重要。在此，通过一种新颖的主客体策略将FeNi-mIm（客体）负载在ZIF-8（主体）表面，所得的ZIF-8@FeNi(mIm)前驱体可转化为具有可控结构的FeNi SAs/NC催化剂。通过对前驱体进行热解，开发出了用于ORR的稳健的金属有机框架（MOF）衍生的原子分散的Fe/Ni双单原子电催化剂。表征表明，原子分散的Fe/Ni活性位点均匀地嵌入在N掺杂的碳框架中。结果，在碱性介质中，ORR性能得到明显改善，半波电位更低（E = 0.91 V）。这种改善主要归因于Fe/Ni 3d轨道相互作用导致的完全暴露的双金属单原子活性位点的协同作用。通过密度泛函理论计算了活性位点上中间羟基的较低吸附能和较小的ORR能垒。新型的FeNi SAs/NC催化剂在四电子转移的速率决定步骤中显示出更快的ORR动力学。本文报道的合成策略提供了一种有效的方法来构建表面具有完全暴露活性位点的高性能双单原子催化剂。
