Hydrogen oxidation reaction (HOR) can be applied to proton exchange membrane fuel cells to generate electrical energy and anode discharge. Due to its special properties, RuO2 has been applied to supercapacitors, phenolic wastewater, textile industry wastewater, and degrading organic substances. However, there is few reports on the application of the RuO2 catalyst to hydrogen oxidation reaction (HOR). In this study, we successfully obtained RuO2 NPs using a simple and eco-friendly hydrothermal method. Furthermore, the electrochemical activity of RuO2 NPs prepared at different concentration (0.15 M, 0.20 M) and different hydrothermal temperature (150 degrees C, 160 degrees C, and 170 degrees C) was evaluated by the hydrogen oxidation reaction. The particle size, composition, dispersion and morphology of the obtained RuO2 catalysts were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). In addition, cyclic voltammograms (CV) were utilized to investigate the electrochemical activity of the RuO2 catalysts. The results showed that the obtained catalyst at a hydrothermal temperature of 160 degrees C and a concentration of 0.15 M displayed a Brunauer-Emmett-Teller (BET) surface area of 26.74 m(2) g(-1). Meanwhile, the catalyst had a uniform distribution. The hydrogen oxidation current density of the obtained RuO2 catalysts is upto 6 mA cm(-2), showing a good electrochemical activity for hydrogen oxidation reaction. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.