Xiangyu Guo

CH ₄ ‐rich coal‐bed methane (CBM) is often contaminated with N ₂ , but their similar properties make conventional separation energy‐intensive and inefficient. Herein, we report a photocatalytic strategy for selective N ₂ conversion over CH ₄ , achieving simultaneous CBM purification and nitrogen valorization. A Co‐Ni metal‐organic framework (CoNi‐PYZ) features isolated bimetallic sites, where ligand/Co units donate electrons to Ni, establishing spatially separated reduction and oxidation centers. This structural motif drives a photocatalytic cascade nitrogen fixation that N ₂ is first reduced to NH ₃ at the Ni sites; subsequently, the generated NH ₃ outcompetes CH ₄ for the Co sites, leading to its oxidation to NO ₃ ^– . This remarkable selectivity is governed by the high polarity and lone‐pair electron donation of NH ₃ , favoring its adsorption over nonpolar CH ₄ . Notably, the optimal catalyst achieves high activity under mild conditions without sacrificial agents, delivering NH ₄ ⁺ and NO ₃ ^– production rates of 599.8 and 199.8 µmol g ^{− 1} h ^{− 1} , respectively. Mechanism analysis reveals that ligand engineering optimizes the d‐band center to balance adsorption and desorption, thereby minimizing the rate‐determining step barriers for both half‐reactions, consistent with the Sabatier principle. This work provides a reaction‐driven alternative to traditional phase‐separation, establishing a novel paradigm for CBM upgrading coupled with selective N ₂ transformation.

CH ₄ ‐rich coal‐bed methane (CBM) is often contaminated with N ₂ , but their similar properties make conventional separation energy‐intensive and inefficient. Herein, we report a photocatalytic strategy for selective N ₂ conversion over CH ₄ , achieving simultaneous CBM purification and nitrogen valorization. A Co‐Ni metal‐organic framework (CoNi‐PYZ) features isolated bimetallic sites, where ligand/Co units donate electrons to Ni, establishing spatially separated reduction and oxidation centers. This structural motif drives a photocatalytic cascade nitrogen fixation that N ₂ is first reduced to NH ₃ at the Ni sites; subsequently, the generated NH ₃ outcompetes CH ₄ for the Co sites, leading to its oxidation to NO ₃ ^– . This remarkable selectivity is governed by the high polarity and lone‐pair electron donation of NH ₃ , favoring its adsorption over nonpolar CH ₄ . Notably, the optimal catalyst achieves high activity under mild conditions without sacrificial agents, delivering NH ₄ ⁺ and NO ₃ ^– production rates of 599.8 and 199.8 µmol g ^{− 1} h ^{− 1} , respectively. Mechanism analysis reveals that ligand engineering optimizes the d‐band center to balance adsorption and desorption, thereby minimizing the rate‐determining step barriers for both half‐reactions, consistent with the Sabatier principle. This work provides a reaction‐driven alternative to traditional phase‐separation, establishing a novel paradigm for CBM upgrading coupled with selective N ₂ transformation.

Metal-organic framework (MOF) glasses represent an emerging frontier in porous materials that uniquely combine the structural tunability of crystalline MOFs with the superior processability commonly found in traditional polymers. Unlike their crystalline counterparts, MOF glass-based membranes inherently eliminate grain boundary defects and display excellent thermal stability. The melt-quenching process also enables the formation of unsaturated metal sites and coordination defects, which can be tailored to optimise adsorption affinity, pore size distribution, and diffusion pathways. This review provides a comprehensive overview of the formation mechanisms, structural features, classifications, and advanced characterisation of MOF glass-based membranes, with a focus on their roles in high-selectivity and scalable gas separation. It further discusses the design principles of meltable MOFs, the structural evolution during the crystal-to-glass transition, and critical structure–property relationships. Key challenges fabrication and industrial integration are evaluated, and future research directions are proposed to guide the development of MOF glass membranes as a transformative platform in separation science.