Luo Xiaodong, Ma Hui, Ren Hang, Zou Xuhui, Wang Yuan, Li Xi, Shen Zhangfeng, Wang Yangang, Cui Lifeng
College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, China; Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, China.
J Colloid Interface Sci. 2021 May 15;590:622-631. doi: 10.1016/j.jcis.2021.01.097. Epub 2021 Feb 2.
Sufficient and well-distributed active sites and highly conductive carbon matrix are two important factors to achieve highly efficient electrocatalysts. In this study, we report an adjusted metal-organic frameworks (MOF)-based route for the preparation of nitrogen-doped Fe/Co bimetallic electrocatalysts. With suitable Fe/Co molar ratio (Fe/Co = 1/4.15), Co nanoparticles (NPs) with mild oxidation state and CoFe alloys wrapped with thin graphene layers are embedded in an integrated and continuous carbon network. The corresponding FC@NCs-4.15 catalyst exhibits excellent oxygen reduction reaction (ORR) activity (onset potential (E) of 0.94 V and half-wave potential (E) of 0.84 V vs RHE) in alkaline medium, close to commercial Pt/C and superior to the other two FC@NCs. The desirable ORR performance results from the uniform distribution CoFe active sites, electron density modification from Co NPs to surrounding carbon layers, hierarchical pore structure with large surface area, low carbon content, high pyridinic and graphitic N components. The FC@NCs-4.15 also displays satisfactory methanol crossover tolerance and durability.
充足且分布均匀的活性位点以及高导电性的碳基质是实现高效电催化剂的两个重要因素。在本研究中，我们报道了一种基于调整后的金属有机框架（MOF）的路线来制备氮掺杂的铁/钴双金属电催化剂。通过合适的铁/钴摩尔比（Fe/Co = 1/4.15），具有温和氧化态的钴纳米颗粒（NPs）以及包裹着薄石墨烯层的钴铁合金被嵌入到一个完整且连续的碳网络中。相应的FC@NCs - 4.15催化剂在碱性介质中表现出优异的氧还原反应（ORR）活性（相对于可逆氢电极（RHE），起始电位（E）为0.94 V，半波电位（E）为0.84 V），接近商业铂碳催化剂且优于另外两种FC@NCs。这种理想的ORR性能源于均匀分布的钴铁活性位点、从钴纳米颗粒到周围碳层的电子密度修饰、具有大表面积的分级孔结构、低碳含量、高吡啶型和石墨型氮成分。FC@NCs - 4.15还表现出令人满意的甲醇透过耐受性和耐久性。
