pH-Induced Size Regulation of Ru Nanocrystals and the Applications Towards Proton Exchange Membrane Water Electrolysis

Ruthenium(Ru) and its derivatives have been widely studied as oxygen evolution reaction(OER) electrocatalysts in acidic water electrolysis due to their inherent electronic properties and high oxygen evolution activity. A facile pH-induced size regulation approach for Ru nanocrystals has been developed by introducing NaOH and CH 3 COOH in a polyol system. The size of Ru particles decreases with the increase of the dosage of NaOH and increases at a certain dosage of CH 3 COOH. The formation mechanism of ruthenium nanocrystals was investigated through a series of characterizations and kinetic experiments. The electrocatalytic activities of the electrocatalysts derived from these Ru particles were studied toward OER to investigate the influence of particle size on their electrocatalytic properties. Moreover, the prepared electrocatalysts were applied as anodic materials in the proton exchange membrane(PEM) electrolysis cell and demonstrated excellent performance.