Innovative catalyst advances acidic water splitting technology

Researchers from the Shanghai Institute of Ceramics of the Chinese Academy of Sciences, together with collaborators, have made a significant breakthrough in electrocatalytic water splitting, a key technology for converting intermittent solar and wind energy into clean hydrogen fuel.

According to the study published in Science Advances, quinary high-entropy ruthenium iridium-based oxide holds promise for large-scale application in proton exchange membrane water electrolyzer (PEMWE).

In the pursuit of a hydrogen society, electrocatalytic water splitting has emerged as a potential solution. However, the acidic operating environment of the proton exchange membrane (PEM) has posed challenges for the long-term use of ruthenium oxide (RuO₂). Now, the researchers led by Prof. Wang Xianying have discovered a quinary high-entropy five-membered ruthenium iridium-based oxide (M-RuIrFeCoNiO₂), which has promising applications in PEMWE.

They developed a unique synthesis strategy for M-RuIrFeCoNiO₂ to create abundant grain boundaries (GBs). This innovation significantly improves the catalytic activity and stability of RuO₂ in acidic oxygen evolution reactions (OER), overcoming previous limitations.

The deliberate integration of foreign metal elements and GBs into the oxide catalyst played a pivotal role in improving OER activity and stability. This groundbreaking approach effectively solves the thermodynamic solubility problems associated with different metal elements.

Practical application tests showed remarkable results, as a PEMWE using the M-RuIrFeCoNiO₂ catalyst maintained a high current density of 1 A cm^-2 for more than 500 hours. This achievement marks a significant advancement in PEMWE technology and holds promise for the large-scale production of clean hydrogen fuel.

This study not only demonstrates a novel synthesis strategy for high entropy oxides, but also provides valuable insights into their activity and stability in the context of PEMWE, contributing to the advancement of clean energy solutions.