Preparation of the acid treated active carbon-supported Pd/Pt nanocatalyst for oxygen reduction reaction in advanced Chlor-Alkali

In this investigation, the active carbon supported Pt/Pd nanocatalyst was synthesized usingborohydride reduction method. The activated carbon was treated in different acidic mediacomposed of HNO3 and H2SO4, with the aim of distinguishing whether the electrocatalyticactivity of the nanocatalyst is preferentially driven by acid treatment method. The carbonsupported nanocatalysts were characterized by SEM/EDAX and XRD. The electrocatalyticactivities of the glassy carbon electrode covered by the catalysts were estimated by cyclicvoltametery, Tafel polarization and hydrodynamic voltametery. The SEM/EDAX andmapping analysis has demonstrated that the Pt-Pd/C electrocatalyst containing 30%w w-1 of each metal synthesized based on the concentrated HNO3-treated active carbon hassufficient metal dispersion. Subsequently, the electrochemical characterization by CV,hydrodynamic voltametery and Tafel polarization in alkali O2-saturated medium indicated aproper electrocatalytic activity for this electroatayst in ORR. The overall electron transfernumber was found to be 4 by Koutecky-Levich theory [1]. The results prove a goodselectivity for production of the OH- with respect to the H2O2. Then, the active catalyst wasemployed to prepare the oxygen gas diffuse electrode for operation in advanced Chlor-Alkalitechnology. The setup performance tests were carried out by 300 g L-1 NaCl and NaOH 30%w w-1 as anolyte and catholyte, respectively. The wet oxygen flows through the gas diffusecathode. The obtained operation results at the current density of 5.6 kA m-2 (10 h)reperesented that the energy consumption with this oxygen depolarized electrode (13 cm2) isapproximately 27% less than conventional Chlor-Alkali.