Efficiency Of H2O2 Generation Research Articles

Metal–Organic Framework Fe-BTC as Heterogeneous Catalyst for Electro-Fenton Treatment of Tetracycline

This study explores the use of the iron-containing metal–organic framework (MOF), Basolite®F300, as a heterogeneous catalyst for electrochemically-driven Fenton processes. Electrochemical advanced oxidation processes (EAOPs) have shown promise on the abatement of recalcitrant organic pollutants such as pharmaceuticals. Tetracyclines (TC) are a frequently used class of antibiotics that are now polluting surface water and groundwater sources worldwide. Acknowledging the fast capability of EAOPs to treat persistent pharmaceutical pollutants, we propose an electrochemical Fenton treatment process that is catalyzed by the use of a commercially available MOF material to degrade TC. The efficiency of H2O2 generation in the IrO2/carbon felt setup is highlighted. However, electrochemical oxidation with H2O2 production (ECO-H2O2) alone is not enough to achieve complete TC removal, attributed to the formation of weak oxidant species. Incorporating Basolite®F300 in the heterogeneous electro-Fenton (HEF) process results in complete TC removal within 40 min, showcasing its efficacy. Additionally, this study explores the effect of varying MOF concentrations, indicating optimal removal rates at 100 mg L−1 due to a balance of kinetics and limitation of active sites of the catalysts. Furthermore, the impact of the applied current on TC removal is investigated, revealing a proportional relationship between current and removal rates. The analysis of energy efficiency emphasizes 50 mA as the optimal current, however, balancing removal efficiency with electrical energy consumption. This work highlights the potential of Basolite®F300 as an effective catalyst in the HEF process for pollutant abatement, providing valuable insights into optimizing electrified water treatment applications with MOF nanomaterials to treat organic pollutants.

Catalysis of oxygen reduction reaction for H2O2 electrogeneration: The impact of different conductive carbon matrices and their physicochemical properties

Carbon-based catalysts are widely used in oxygen reduction reactions (ORR) via 2e- for H2O2 electrogeneration. The direct comparability of the structural proprieties of different carbon matrices applied on ORR, however, has never been tested. Here, we evaluate how the electrochemical and structural properties of different carbon-based materials, including carbon Printex XE2B (PXE2BC), Printex L6 (PL6C), carbon derived from lignin (LIGC), graphite (GRA) and glassy carbon (GC), affect on ORR. All the materials were characterized by Raman spectroscopy, X-ray photoelectron spectrometry (XPS), elementary analysis, field emission gun scanning electron microscopy, surface area measurements and electrochemical assays for the evaluation of ORR. Notably, the morphology, the size of the particles and the types of functional groups present in the structure of carbon materials were keys in the efficiency of ORR. The carbon materials PL6C and PXE2BC with high surface area and oxygenated functional groups in their structure displaced the ORR potential, facilitating the reaction. Carbon materials with less surface area, such as GRA, LIGC and GC, and whose main functional groups in their structures were non-oxygenated or nitrogenated, were less active in ORR. The displacement of the potential and the efficiency of H2O2 generation were directly dependent on the electrochemical and structural characteristics of the materials used as catalysts. These results are particularly relevant regarding a proper choice of carbon catalyst can increase the efficiency of ORR.