Impedance spectroscopy of water splitting reactions on nanostructured metal-based catalysts

Functional Materials and Nanotechnologies 2018

Niklasson, G.A.^1 ; Qiu, Z.^1 ; Bayrak Pehlivan, I.^1 ; Edvinsson, T.^1

Department of Engineering Sciences, Uppsala University, P.O. Box 534, Uppsala

SE-75121, Sweden^1

关键词: Electrocatalytic materials;    Equivalent circuit model;    Impedance spectroscopy;    Metal-based catalysts;    Nanostructured metals;    Renewable energy source;    Substrate dependences;    Water splitting reactions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/503/1/012005/pdf
DOI  :  10.1088/1757-899X/503/1/012005

来源: IOP

【 摘 要 】

Hydrogen production by water splitting using nanomaterials as electrocatalysts is a promising route enabling replacement of fossil fuels by renewable energy sources. In particular, the development of inexpensive non-noble metal-based catalysts is necessary in order to replace currently used expensive Pt-based catalysts. We report a detailed impedance spectroscopy study of Ni-Mo and Ni-Fe based electrocatalytic materials deposited onto porous and compact substrates with different conductivities. The results were interpreted by a critical comparison with equivalent circuit models. The reaction resistance displays a strong dependence on potential and a lower substrate dependence. The impedance behaviour can also provide information on the dominating reaction mechanism. An optimized Ni-Fe based catalyst showed very promising properties for applications in water electrolysis.