Bimetallic MOF-235(Fe, Co) Supported on Biomass-Derived Activated Carbon as a Noble-Metal Electrocatalyst for Hydrazine Electrooxidation

Abstract

This study used ZnCl<inf>2</inf>-activated carbon (AC) derived from hazelnut shell waste to fabricate MOF-235(Fe, Co), a bimetallic metal-organic framework composite, which was then used as an electrocatalyst for the electrooxidation of hydrazine (HEOR) in an alkaline medium. FTIR, XRD, SEM-EDX, BET, and XPS investigations were used to examine the synthesized materials' structural, morphological, and surface properties. Vibrational modes, elemental fingerprints, and distinctive diffraction patterns all demonstrated the effective integration of Fe and Co species, confirming the synthesis of MOF-235(Fe, Co) on AC. Chronoamperometry (CA), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and cyclic voltammetry (CV) were used to assess electrochemical performance. With a specific activity of 54.8 mA cm−2 and a low onset potential of 0.81 V, the MOF-235(Fe, Co)/AC-modified glassy carbon electrode (GCE) demonstrated much higher electrocatalytic activity and stability toward hydrazine oxidation as compared to bare GCE and AC/GCE. Additionally, EIS studies showed better reaction kinetics and decreased charge transfer resistance at higher potentials, particularly for MOF-235(Fe, Co)/AC/GCE. The increased number of electroactive sites, advantageous electron transport characteristics, and the synergistic interaction between Fe and Co species were credited with the improved performance. In direct hydrazine fuel cell applications, our results imply that MOF-235(Fe, Co)/AC is a viable noble-metal-free electrocatalyst for effective hydrazine oxidation. © 2025 Elsevier B.V., All rights reserved.