High-performance RuO2/CNT paper electrode as cathode for anion exchange membrane water electrolysis

This study reports on the synthesis and characterization of an effective cathode paper electrode comprising comparatively inexpensive hydrous RuO2 (h-RuO2) nanoparticles on carbon nanotubes (CNT) for anion exchange membrane (AEM) water electrolysis. The concentration of hydrous RuO2 nanoparticles on the CNT was varied to assess their impact on the electrocatalyst for the hydrogen evolution reaction (HER). The electrocatalytic performance of h-RuO2/CNT comprising 22.0 wt% of Ru was evaluated. Promising results were obtained, with a current density of −10 mA/cm2 at only 36 mV of overpotential and a mass activity of −2.41 A/gRu at 100 mV. Additionally, we conducted first-principles calculations to compare the HER catalytic activities of crystalline RuO2 and hydrous RuO2 with varying vacancies and to determine the H2O concentration in the structural lattice using free-energy diagrams. The study findings demonstrate that the h-RuO2/CNT paper can be used as an efficient electrocatalyst for AEM water electrolysis.