Beyond Membranes: Recent Advances in Membrane-Free Fuel Cells.

As energy demand increases and the need for sustainable solutions grows, fuel cells have emerged as a promising solution, capable of converting chemical energy into electricity in a clean and combustion-free process. This technology not only improves energy efficiency but also leads to significant emission reductions, paving the way for a cleaner future. Among the various fuel cell technologies, proton-exchange membrane fuel cells (PEMFCs) have been at the forefront (Abdelkareem et al., Sci. Total Environ. 2021, 752, 141803). However, their broader adoption is hindered by key challenges, including high costs, slow reaction kinetics, and internal resistance, which limit their scalability. In response to these challenges, membraneless fuel cells (MFCs) have emerged as an exciting alternative to polymeric membrane systems. By removing the membrane, the system becomes simpler, improving efficiency and robustness, while offering advantages like lower production and maintenance costs, increased durability, and better resistance to chemical degradation. This review focuses on recent advances in the design and catalysis optimization of MFCs. These advancements offer promising avenues for the widespread adoption of MFCs in sustainable energy applications.