Electrooxidation of hydroquinone on simply prepared Au-Pt bimetallic nanoparticles

A facile method was used to prepare gold-platinum (Au-Pt) catalysts by direct electrodeposition via cyclic voltammetry in an acidic medium. Various parameters that affect the properties of electrodeposited catalysts were investigated such as initial applied potential, scan rate and deposition time. Initial applied potential plays a more important role in the preparation of bimetallic nanoparticles (AuPtNPs) since the kinetics of electrodeposition is in competition with the rate of hydrogen evolution. The AuPtNPs electrodeposited on pencil graphite (PG) were used to study the electrooxidation of hydroquinone. Various parameters such as pH, scan rate, concentration of hydroquinone and temperature were studied in the electrooxidation process. Apparent activation energy (Ea) for the electrooxidation of hydroquinone, calculated from the Arrhenius plot, shows that AuPtNPs catalysts (electrodeposited on the PG) offer less activation energy (ca. 9.500 kJ mol−1) than the bare PG (ca. 10.345 kJ mol−1). The AuPtNPs/PG shows better catalytic performance than the PG electrode due to the greater surface area it provides, thus resulting in more active sites available for adsorption of hydroquinone molecules on the surface of the catalyst.