Gradient Pore-Hydrophobicity Cooperation for Synergistic H2O/CO2 Management toward Efficient Acidic CO2 Electroreduction

Developing acidic electrochemical CO 2 reduction reaction (CO 2 RR) systems can alleviate carbonate clogging in gas diffusion electrodes (GDEs), offering an efficient way to convert CO 2 at industrial-level current densities ( J > 200 mA cm –2 ). However, it comes at the cost of aggravating competitive hydrogen evolution reactions (HERs). Breaking this intrinsic selectivity–stability trade-off requires synergistic H 2 O/CO 2 management. As a central component of GDEs, the gas diffusion layer (GDL) critically governs gas (CO 2 )–liquid (H 2 O) transport balance. This work proposes a gradient pore-hydrophobicity cooperation strategy for synergistic H 2 O/CO 2 management to achieve efficient acidic CO 2 RR. Paired with commercial Ag catalysts, the Ag-GDEs exhibit an impressive CO Faraday efficiency of 97.26% at 400 mA cm –2 within a pH = 2.0 environment. Furthermore, in situ differential electrochemical mass spectrometry confirms the distinct mass transfer kinetics induced by GDL architectures. Lattice Boltzmann modeling simulations corroborate the effects of the gradient pore-hydrophobicity synergy on CO 2 and H 2 O distribution in GDLs. This work presents an effective approach to the rational design of GDLs and the collaborative liquid–gas management for efficient CO 2 RR.