A newly developed covalent organic framework decorated with chromium for efficient methanol fuel cell

Abstract

Covalent Organic Frameworks (COFs) have emerged as a promising class of crystalline porous materials with potential applications in various fields, including catalysis, gas storage, and energy conversion. A novel COF was prepared from the reaction of terephthalaldehyde and tris(2-aminoethyl)amine and characterized using various techniques including Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET) surface area measurement, and thermal analysis. BET analysis revealed a surface area of 507.56 m²/g and an average pore diameter of 8.34 nm. Chromium modification applied to increase its electrocatalytic activity to be used in fuel cells applications. The electrochemical evaluation demonstrated superior catalytic activity of Cr-COF-coated Pt and Au electrodes toward methanol oxidation in alkaline media with current densities of 4.89 mA cm− 2 and 1.79 mA cm− 2 for Pt and Au electrodes, respectively. Also, the Tafel slpoe for Cr-COF/Pt (149 mV dec− 1) and Cr-COF/Au (198 mV dec− 1) were described. Specifically, the Cr-COF/Pt electrode exhibited a current density 2.2 times higher than bare Pt, while Cr-COF/Au achieved a 2.75-fold enhancement compared to bare Au. Moreover, chronoamperometry and electrochemical impedance spectroscopy revealed high stability, low resistance, and efficient charge transfer dynamics. These findings highlighted the potential of Cr-COF as a promising electrocatalyst for direct methanol fuel cells (DMFCs), offering improved activity, stability, and reduced reliance on noble metals.