A porous Cu metal–organic framework (1) based on a pentacarboxylate ligand and paddlewheel SBU was synthesized and structurally characterized. Complex 1 possesses a NbO-type framework with uncoordinated –COO⁻ groups, resulting in its good selectivity for CO₂/N₂ (36) and CO₂/CH₄ (12) as well as a large CO₂-uptake capacity of 140 cm³ g⁻¹ at 273 K and 1 bar. Grand Canonical Monte Carlo (GCMC) simulations revealed that strong CO₂ adsorption sites exist near the open Cu^II sites and the uncoordinated –COO⁻ groups. Significantly, complex 1 exhibits water resistance and selective adsorption of cationic methylene blue (MB⁺) in aqueous solution and the adsorbed MB⁺ can be released in saturated NaCl solution, making it also a promising porous material for charge and pore-size dependent large-molecule capture and separation. The existence of coordinatively unsaturated metal sites as well as the exposed –COO⁻ groups in the framework of 1 is responsible for its selective gas adsorption and dye separation.

The development of low‐cost, high‐efficiency, and stable electrocatalysts for hydrogen evolution reaction (HER) under alkaline conditions is a key challenge in water electrolysis. Here, an interfacial engineering strategy that is capable of simultaneously regulating nanoscale structure, electronic structure, and interfacial structure of Mo₂N quantum dots decorated on conductive N‐doped graphene via codoping single‐atom Al and O (denoted as AlO@Mo₂N‐NrGO) is reported. The conversion of Anderson polyoxometalates anion cluster ([AlMo₆O₂₄H₆]³⁻, denoted as AlMo6) to Mo₂N quantum dots not only result in the generation of more exposed active sites but also in situ codoping atomically dispersed Al and O, that can fine‐tune the electronic structure of Mo₂N. It is also identified that the surface reconstruction of AlOH hydrates in AlO@Mo₂N quantum dots plays an essential role in enhancing hydrophilicity and lowering the energy barriers for water dissociation and hydrogen desorption, resulting in a remarkable alkaline HER performance, even better than the commercial 20% Pt/C. Moreover, the strong interfacial interaction (MoN bonds) between AlO@Mo₂N and N‐doped graphene can significantly improve electron transfer efficiency and interfacial stability. As a result, outstanding stability over 300 h at a current density higher than 100 mA cm⁻² is achieved, demonstrating great potential for the practical application of this catalyst.