Electrocatalytic performance of synthesized sawdust biochar-based adsorbents as electrocatalysts for methanol electrooxidation in fuel cells

In order to electrocatalytically oxidize methanol in an alkaline media, the catalytic activity of Pb2+, Cd2+, Cu2+ and Fe2+-loaded sawdust (Ms-LSD) adsorbents and their combination with Pb2+, Cd2+, Cu2+ and Fe2+-loaded sawdust biochar (Ms-LSDBC) adsorbents made from sawdust were investigated. Several instrument methods, including energy dispersive X-ray spectroscopy (EDX), X-ray diffraction analysis (XRD), field emission scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR), were used to characterize Ms-LSD and Ms-LSDBC. These findings verified that the functional groups and crystalline intensity peaks of the SD and SDBC catalysts changed when Ms were loaded onto them. On a modified glassy carbon electrode (GCE), a combination of 0.5 M KOH and 1 M CH3OH was used to evaluate the electrocatalytic performance of Ms-LSD and Ms-LSDBC. At 0 to 0.6 V with a scan rate of 50 mV/s, the Ms-LSDBC demonstrated a high current density and a noticeably better electrocatalytic performance than the Ms-LSD, particularly, Fe2+-LSDBC (95.90 mA/cm-2) and Fe2+-LSD (5.51 mA/cm-2) verified superior electrocatalytic methanol oxidation and a higher current density. Compared to Ms-LSD, Ms-LSDBC has reduced charge transfer resistance (Rct) values. Throughout the entire 1000 s test period for methanol oxidation, the Ms-LSDBC catalysts demonstrated superior stability and greater catalytic activity compared to the Ms-LSD catalysts in 0.5 M KOH with 1 M CH3OH at 0.1 V. These findings highlighted the Ms-LSDBC potential as a significant electrocatalyst for fuel cell methanol oxidation.