Design of precursors and pH factors for enhancing the performance of nickel-based catalysts for anion exchange membrane water electrolysis

Abstract

In response to the escalating global energy crisis and climate change, green hydrogen is increasingly recognized as a clean energy solution. This study presents an innovative approach to enhance the performance of nickel-based catalysts for anion exchange membrane water electrolysis (AEMWE) through careful selection of precursor materials and pH optimization in the co-precipitation process. By optimizing precursor types and pH conditions during co-precipitation synthesis, we achieved high yields of Ni(OH)2, which were then thermally treated to form NiO. Notably, the nitrate-based NiO (N-NiO) exhibited superior catalytic activity and durability, attributed to its favorable microstructure and charge transfer capabilities. In addition, to verify universality of the N-NiO study and to assess the water electrolysis performance, we synthesized a binary compound, nickel–cobalt oxide (NCO), by incorporating Co, and evaluated its electrochemical performance in an AEMWE single-cell system. The nitrate-based NCO-based single-cell achieved a high current density of 1.38 A/cm2 at 1.8 Vcell in 1 M KOH at 50 °C, with a low degradation rate of 23 mV/kh at 1 A/cm2 for 300 h. These findings provide valuable insights into the optimization of catalyst properties for hydrogen production and highlight significant commercial potential for hydrogen production and other electrochemical applications.

Keywords

• Anion exchange membrane water electrolysis
• Green hydrogen
• Oxygen evolution reaction
• Co-precipitation
• Precursors
• Ni-based electrocatalyst