Catalytic wet peroxide oxidation with in-situ generated H2O2: An efficient strategy for improving the stability of metal-organic framework catalysts

• Published in: Catalysis today Vol. 425; p. 114316
• Main Authors: Vo, Viet Le Nam, Luu, Thi-Thuy, Chung, Young-Min
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2024
• Subjects: Catalytic wet peroxide oxidation; Direct synthesis of H2O2; Metal-organic frameworks; Organic dye degradation; Organic dye degradation; Catalytic wet peroxide oxidation; Metal-organic frameworks; Direct synthesis of H2O2
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2023.114316

Although catalytic wet peroxide oxidation (CWPO) may offer an efficient method for wastewater treatment, the use of metal-organic framework (MOF) catalysts for the CWPO reaction in the presence of H2O2 is challenging because the MOF structure is highly vulnerable to water and/or oxidizing agents. Herein, a range of M-1,3,5-benzenetricarboxylate (BTCs) (M = Fe, Co, Mn, and Cu) were prepared, and their catalytic activities in the CWPO of methyl orange (MO) were evaluated. To examine the stability of the M-BTCs under different reaction conditions, the CWPO reaction was performed with ready-made H2O2 (CWPO-I) or in-situ generated H2O2 using H2 and O2 (CWPO-II). In the latter, Pd was supported onto an M-BTC (Pd/M-BTC). The CWPO-I reaction rate was significantly affected by the metal nodes of the M-BTC, with the Fe-BTC catalyst showing the fastest MO degradation rate. However, regardless of the type of metal node, the M-BTC catalysts underwent significant decomposition during the CWPO-I reaction, leading to a considerable decrease in their textural properties. This result suggests that the M-BTC structure collapsed due to attack by the hydroxyl radicals generated during the reaction. Therefore, the activity of the regenerated Fe-BTC catalyst significantly decreased to 40% of that of the fresh catalyst. In contrast, the catalyst stability in CWPO-II outperformed that in CWPO-I. The Pd/Fe-BTC catalyst exhibited a moderate decrease in activity owing to the gradually reduced surface area of the catalyst during the recycling runs, and the crystallinity of Fe-BTC was preserved. Moreover, the content, particle size, and electronic properties of Pd supported on Fe-BTC showed little change after the reaction. These results demonstrate that the use of in-situ generated H2O2 is superior for impeding the catalyst deactivation caused by structural deformation of the MOF. [Display omitted] •Catalytic wet peroxidation (CWPO) of methyl orange was performed with MOF catalysts.•M-BTC and Pd/M-BTC (M=Fe, Co, Mn, Cu) catalysts were prepared and evaluated.•The CWPO reaction was carried out with ready-made or in-situ generated H2O2.•Activity and stability of catalyst highly depend on the metal of M-BTC and reaction types.•Use of in-situ generated H2O2 was superior in retarding catalyst deactivation.