PdZrO₂/rGO-FTO as an effective modified anode and cathode toward methanol electro-oxidation and hydrogen evolution...

In the present work, Pd/rGO and PdZrO₂/rGO nanostructures were synthesized in a single step by hydrothermal method. Synthesized nanostructures containing 20 wt% Pd nanoparticles were characterized and approved using Fourier-transform infrared spectroscopy, x-ray diffraction, field emission scanning electron microscopy, energy-dispersive x-ray spectroscopy, and transmission electron microscopy techniques. The performance of Pd and PdZrO₂hybridized with rGO as catalysts were investigated and compared in the process of hydrogen production by water electrolysis and also in the process of electricity generation by methanol oxidation in the fuel cell. The activity and stability of synthetic nanocatalysts were evaluated using cyclic voltammetry, LSV, and chronoamperometry. The results showed that the presence of ZrO₂in the nanostructure increases the current density and reduces the overvoltage of the catalytic process. For methanol oxidation reaction, PdZrO₂/rGO catalyst displays 92 mA cm^-2current density in alkaline media. For hydrogen evolution reaction, the Tafel slope of 52 mV dec^-1and overpotential of -0.198 V at the current density of 10 mA cm^-2were obtained in alkaline media. Also, due to high stability, this catalyst can be recommended as an optimal catalyst for industrial processes.