Highly efficient electrodes with facile fabrication, enhanced reaction sites, low cost, and acceptable durability are of paramount significance for the development of gigawatt-scale proton exchange membrane electrolyzer cells (PEMECs).1-4 In this study, IrRuOx catalysts with high activity are firstly electroplated on titanium liquid/gas diffusion layers via a facile electroplating process at room temperature, serving as highly efficient integrated anode electrodes in PEMECs. When assembled with a PEMEC, low cell voltages of 1.620 and 1.867 V are achieved at 2 and 6 A/cm2, respectively, achieving high cell efficiency of above 91% at 2 A/cm2, superior to the commercial CCM. Moreover, the IrRuOx integrated electrode shows low-performance loss during a 500-h operation at a high current density of 5 A/cm2, and a degradation rate of less than 40 μV/h is observed in the last 250 h, as shown in the figure. The remarkable performance and stability of the IrRuOx integrated electrode are mainly due to the excellent electrode design, high intrinsic activity of amorphous IrRuOx catalysts exposing abundant active sites and a well-controlled Ir and Ru ratio. References Mo, Jingke, Zhenye Kang, Scott T. Retterer, David A. Cullen, Todd J. Toops, Johney B. Green Jr, Matthew M. Mench, and Feng-Yuan Zhang. "Discovery of true electrochemical reactions for ultrahigh catalyst mass activity in water splitting." Science advances 2, no. 11 (2016): e1600690.Xie, Zhiqiang, Shule Yu, Xiaohan Ma, Kui Li, Lei Ding, Weitian Wang, David A. Cullen et al. "MoS2 nanosheet integrated electrodes with engineered 1T-2H phases and defects for efficient hydrogen production in practical PEM electrolysis." Applied Catalysis B: Environmental 313 (2022): 121458.Yang, Gaoqiang, Shule Yu, Zhenye Kang, Yifan Li, Guido Bender, Bryan S. Pivovar, Johney B. Green Jr, David A. Cullen, and Feng‐Yuan Zhang. "Building electron/proton nanohighways for full utilization of water splitting catalysts." Advanced Energy Materials 10, no. 16 (2020): 1903871.Kang, Zhenye, Jingke Mo, Gaoqiang Yang, Scott T. Retterer, David A. Cullen, Todd J. Toops, Johney B. Green Jr, Matthew M. Mench, and Feng-Yuan Zhang. "Investigation of thin/well-tunable liquid/gas diffusion layers exhibiting superior multifunctional performance in low-temperature electrolytic water splitting." Energy & Environmental Science 10, no. 1 (2017): 166-175. Figure 1