Abstract The development of high-performance gas diffusion electrodes (GDEs) is critical for scalable and sustainable electrochemical H2O2 production. However, conventional catalyst layers (CLs) suffer from catalyst encapsulation by fused polytetrafluoroethylene (PTFE) and disordered pore structures, forming a mass transport maze that restricts species diffusion and degrades three-phase interface (TPI) formation. Here, we introduce a non-fused particulate-packed catalyst/binder interface that forms discrete hydrophilic–hydrophobic domains and eliminates the insulating “PTFE armor”. Through 3D reconstruction and high-resolution lattice Boltzmann simulations, we identify that localized variations in wettability and pore structure critically govern electrolyte intrusion and sustaining effective TPIs. Inspired by these insights, we construct a gradient CL featuring hierarchical porosity and precisely tune wettability gradients. Multiscale simulations, in-situ breakthrough pressure measurements, and microfluidic experiments reveal that this gradient design enables directional electrolyte transport and propels H2O2 away from CL, maintaining stable Faradaic efficiency (> 85%) at 300 mA cm− 2 over 300 hours. Moreover, we develop a commercialized scale-up 400 cm2 four-unit flow-through cell stack integrated with thermal, fluidic, and electronic systems, capable of continuously producing H2O2 at a low cost (0. 381 kg− 1) without external oxygen. We demonstrate that catalyst/binder interfaces govern microscale mass transport and TPI formation, with ordered porosity and wettability gradients synergistically boosting electrode performance. This work provides a fundamental design framework for next-generation GDEs and showcases a milestone demonstration of a breakthrough integrated self-breathing H2O2 electrosynthesis system with compelling commercial viability.
Ye et al. (Mon,) studied this question.