The Influence of Ni Content in NixCoy‐BDC Metal‐Organic Frameworks on Catalytic Activity for Hydrogen Generation from Sodium Borohydride

ABSTRACT Mono‐ and bimetallic Ni/Co‐based metal–organic frameworks (MOFs) coordinated with 1,4‐benzenedicarboxylate were successfully synthesized via a solvothermal approach and characterized by PXRD, FTIR, TGA, SEM–EDS, TEM, BET, and XPS. Fine control over the Ni:Co molar ratio enabled systematic modulation of the structural and electronic properties of the MOFs, leading to pronounced differences in catalytic performance and stability toward hydrogen generation from sodium borohydride (NaBH 4 ). Among the catalysts, the bimetallic Ni 2 Co 1 ‐BDC MOF delivered outstanding performance, achieving a hydrogen generation rate of 2493.0 mL min −1 g −1 at 45°C and an efficiency of 94%. This sample also showed the highest surface area (54 m 2 g −1 ), the smallest crystallite sizes (14.67 nm), and the most uniform morphology. Moreover, nickel incorporation significantly enhanced catalyst durability, with Ni 2 Co 1 ‐BDC retaining approximately 80% of its initial activity after seven consecutive cycles without the need for catalyst regeneration. Thermodynamic parameters exhibit that catalytic performance is governed not only by the energetic barrier but also by entropic contributions, with bimetallic systems benefiting from favorable entropy effects (Δ S ‡ = +23.9 J·mol −1 K −1 ).