Oxygen-Vacancy-Engineered Cu/Cu2O/CuO@C nanocomposites from Copper–Furan 2, 5-Dicarboxylic acid Metal-Organic Framework: Unlocking catalytic Mastery in nitroarene hydrogenation

Abstract

The development of high-performance, multifunctional catalysts capable of effectively addressing nitroarene hydrogenation remains a significant challenge. In this study, we present a novel approach to catalyst design through the controlled carbonization of a copper–furan dicarboxylate metal–organic framework (Cu-FDCA MOF), resulting in two distinct nanocomposites: oxygen-vacancy-rich Cu/Cu₂O/CuO@C (synthesized in an argon atmosphere) and conventional CuO (prepared by air calcination). Advanced characterizations, including TEM, XPS, EPR, and BET, reveal that Cu/Cu₂O/CuO@C possesses 2.3 times more oxygen vacancies and a surface area 97 times greater (106.21 m²/g vs. 1.09 m²/g) than CuO, which directly correlates with its superior catalytic performance. In the context of nitroarene hydrogenation, Cu/Cu₂O/CuO@C demonstrates an exceptionally high rate constant (k_app = 25.33 × 10^-2 s^-1), outperforming CuO by a factor of 40. Furthermore, Cu/Cu₂O/CuO@C maintains 90 % of its catalytic activity after five reaction cycles and can be fully regenerated upon treatment at 400 °C. Through a combination of experimental studies and density functional theory (DFT) calculations, we propose a novel water-derived hydrogen transfer mechanism that challenges conventional understanding of the role of NaBH₄. Notably, Cu/Cu₂O/CuO@C also exhibits impressive versatility, efficiently degrading organic dye (Congo red/methylene blue/methyl blue) within three minutes. This work establishes MOF-derived oxygen-deficient nanocomposites as promising platforms for both amine synthesis and environmental decontamination.