Construction of Pd-doped RuO 2 nanosheets for efficient and stable acidic water oxidation

RuO 2 has been considered a potential alternative to commercial IrO 2 for the oxygen evolution reaction (OER) due to its superior intrinsic activity. However, its inherent structure dissolution in acidic environments restricts its commercial applications. In this study, we report a novel Pd-doped ruthenium oxide (Pd-RuO 2 ) nanosheet catalyst that exhibits improved activity and stability through a synergistic effect of Pd modulation of Ru electronic structure and the two-dimensional structure. The catalyst exhibits excellent performance, achieving an overpotential of only 204 mV at a current density of 10 mA cm - 2 . Impressively, after undergoing 8000 cycles of cyclic voltammetry testing, the overpotential merely decreased by 5 mV. The PEM electrolyzer with Pd 0.08 Ru 0.92 O 2 as an anode catalyst survived an almost 130 h operation at 200 mA cm - 2 . To elucidate the underlying mechanisms responsible for the enhanced stability, we conducted an X-ray photoelectron spectroscopy (XPS) analysis, which reveals that the electron transfer from Pd to Ru effectively circumvents the over-oxidation of Ru, thus playing a crucial role in enhancing the catalyst ' s stability. Furthermore, density functional theory (DFT) calculations provide compelling evidence that the introduction of Pd into RuO 2 effectively modulates electron correlations and facilitates the electron transfer from Pd to Ru, thereby preventing the overoxidation of Ru. Additionally, the application of the two-dimensional structure effectively inhibited the aggregation and growth of nanoparticles, further bolstering the structural integrity of the catalyst. (c) 2023 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).