铁镍合金催化剂的结构调控及对电化学析氧反应的催化性能

以碳纤维纸(CFP)为基底材料, 通过水热生长铁镍前驱体、 多巴胺包覆和焙烧转化的方法制备出FeNi合金纳米颗粒@氮掺杂碳(FeNi alloy@NC)复合催化剂. 通过改变反应体系中Fe/Ni前驱体的摩尔比可改变合金组成为Fe_0.64Ni_0.36和FeNi₃, 同时催化剂微观结构也由纳米管状变为花状团簇以及片层结构. 在碱性介质中进行电化学析氧反应测试, 发现 FeNi₃@NC(1∶3)催化剂表现出了最优的催化活性和稳定性, 合金颗粒与NC层的协同相互作用、 NC保护层的构建以及催化剂的三维微观立体结构是催化剂性能优异的主要原因.

Tuning Microstructures of Iron-Nickel Alloy Catalysts for Efficient Oxygen Evolution Reaction †

N-doped carbon(NC) coated iron-nickel alloy catalysts loaded on the carbon fiber papers(CFP) were prepared by firstly hydrothermal depositing iron-nickel based hydroxide/carbonates, then coating dopamine on their surface, and finally annealing the materials. Particularly, the active alloy species can be tuned to be Fe_0.64Ni_0.36 and FeNi₃ and the microscopic structures of the catalysts show to be nanotubes, nanoflowers and nanosheets upon different atomic ratio of Fe²⁺ to Ni²⁺. In an alkaline media, the FeNi₃@NC(1∶3) catalyst exhibits superior oxygen evolution reaction catalytic activities, which only requires an overpotential of 277 mV to reach a current density of 20 mA/cm². At the same time, FeNi₃@NC(1∶3) displays no obvious activity loss after continuous running for 30 h at 20 mA/cm², indicating a good durability. The excellent performances of the alloy catalysts in alkaline solution can be ascribed to their microstructural features: (1) The composites made by NC shell and alloy cores create copious active sites; (2) The NC coating layer prevents the erosion of alloy nanoparticles which thus improves the durability; (3) The three-dimensional structures well promote mass transfer and effectively suppress the gas peeling effect.