Developing Advanced Mg-Based Solid-State Materials for Gas Separation and Purification: A Review

Magnesium (Mg) is globally abundant in resources, and Mg-based compounds—such as magnesium based hydrides, hydroxides, oxides, and magnesium metal-organic frameworks (Mg MOFs)—have shown significant application prospects in gas separation. This is largely due to the electronic characteristics of Mg or Mg²⁺ ions, which facilitate the capture of hydrogen (H₂) and acidic gases such as carbon dioxide (CO₂) and sulfur dioxide (SO₂) from other gases. Consequently, exploring the use of Mg-based materials in gas separation and purification applications could not only advance the scientific understanding of solid-gas interaction mechanisms but also provide cost-effective solutions for gas separation technology at an industrial level. This review summarizes the recent practices and explorations of Mg-based solid-state materials in various gas separation and purification methods, including physical adsorption-based separation, chemical absorption-based separation, and membrane-based separation. For each separation method, the relevant Mg-based materials are discussed in detail, and key findings from existing research are presented and analyzed. Additionally, inspired by the straightforward design of air-stable hydrogen storage materials, this review specifically addresses anti-passivation strategies for Mg-based hydrides, which are crucial for their applications in hydrogen gas separation and purification. Finally, this review highlights key issues and fields for future research and development in Mg-based gas separation materials.