<p>This study investigates using waste cenosphere from coal combustion to develop low-cost ceramic supports for hydrogen separation membranes. Cenosphere supports were synthesized under various conditions of binders, sintering temperatures, and compaction pressures, then modified with alumina and coated with γ-alumina and NaX zeolite layers. Characterization via XRD, SEM, and particle size analysis enabled the evaluation of membrane performance in H₂/N₂ and H₂/HCl separations. Results showed that the optimized cenosphere support achieved a H₂ permeance of 1.7 × 10⁻⁹mol/(m² s Pa) and a H₂/N₂ separation factor of 1.31. Alumina modification improved membrane properties, as a 65:35 ratio of cenosphere to alumina yielded the highest H₂ permeance. Introducing a γ-alumina intermediate layer further boosted H₂/N₂ separation factor to 3.67. Finally, the NaX zeolite-coated membrane delivered selectivities of 6.2 for H₂/N₂ and 7.54 for H₂/HCl. These observations highlight the feasibility of reusing industrial waste cenosphere as an economic support for hydrogen separation membranes with scope for further optimization. The approach also underscores the synergy between waste valorization and advanced membrane technology, potentially lowering the environmental footprint of hydrogen production while fostering circular economy principles. Although current selectivities and permeances are moderate, these outcomes lay the foundation for future refinements to meet industrial performance requirements in hydrogen purification applications and widespread commercial deployment.</p> Graphical abstract <p></p>