Investigation on borohydride oxidation performance of activated charcol supported palladium-bismuth nanoparticles electrocatalyst for fuel cell application

In this study, bimetallic palladium-bismuth nanoparticles electrocatalysts were synthesized by easy chemical reduction method at room temperature and then electrocatalytic performance of as-prepared catalysts was investigated for borohydride oxidation reaction. Catalysts were prepared here with different mass ratio of Pd to Bi (Pd_xBi_y/Charcoal) to perform comparative study of their borohydride oxidation performance and stability. Characterization of physical properties of prepared catalysts were carried out by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The electrochemical measurements were conducted by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The Pd₅₀Bi₅₀/Charcol electrocatalyst showed the best electrocatalytic performance toward borohydride electro-oxidation. Electrocatalytic response with operating temperature variation is examined and activation energy is calculated as 8.82 kJ mol⁻¹ for Pd₅₀Bi₅₀/Charcol electrocatalyst. The charge transfers resistance (R_ct) and open circuit voltage are measured as 71.6 ohms and 1.76 V respectively for Pd₅₀Bi₅₀/Charcol electrocatalyst. Change in catalytic performance in different concentration of NaBH₄ are also measured.