Optimization of electrode preparation conditions by response surface methodology for improved formic acid electrooxidation on Pd/MWCNT/GCE

Abstract

Abstract This work examines the formic acid electrooxidation (FAEO) capabilities of Pd catalysts supported by multiwall carbon nanotubes (MWCNTs) that were synthesized at varying weight percentages. Advanced surface analysis techniques namely X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy with X-ray energy dispersive (SEM-EDX), and elemental mapping are used to evaluate the Pd/MWCNT. To achieve the highest specific activity for FAEO on Pd/MWCNT, electrode preparation parameters namely catalyst slurry amount (Vs), ultrasonication duration of catalyst slurry (tu), and electrode drying time (td) were optimized by response surface methodology central composite design (RSM-CCD). Measurements made using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) are used to determine the specific activity and stability for FAEO. The optimum values for the Vs, td, and tu were determined as 1.84 µl, 45 min, and 37.05 min while under these optimum conditions, the specific activity for FAEO on Pd/MWCNT was 2.67 mA cm-2 with a deviation of 6.83%. By optimizing the electrode preparation conditions, a conventional Pd/MWCNT catalyst showed higher performance than many bimetallic catalysts. Optimization of electrode preparation parameters is as important as catalyst design and is an inexpensive and facile method to improve electrocatalytic performance.