Xiaoke Li, Xuejing Cui, Luhua Jiang*

Nanomaterials & Electrocatalysis Laboratory, College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R. China

Corresponding author: ^*E-mail address: luhuajiang@qust.edu.cn

Abstract

Oxygen evolution reaction (OER) and urea oxidation reaction (UOR) limit the efficiency of electrolytic water and urea oxidation to hydrogen formation processes, respectively. Here, a facile low-temperature anhydrous method was used to synthesize NixFey-LDHs catalysts with good eletrocatalytic activity for OER and UOR. With urea oxidation as an alternative anodic reaction, the anodic oxidation potential decreased significantly to 1.37 V@20 mA cm^-2. The electrolyzer voltage decreased to only 1.41 V@10 mA cm^-2 with the Ni₉Fe₁-LDHs anode. It was demonstrated that Fe induced the formation of Ni(III) on the surface and promoted the reversible Ni(II)/Ni(III) transition.

Keywords: Urea oxidation reaction; Oxygen evolution reaction; Layered double hydroxide; Hydrogen production.

https://doi.org/10.1016/j.catcom.2021.106390