Binary Fe-Pd nanoflakes anchored on porous graphite coin electrode forenhanced electrocatalytic oxygen reduction

Porous graphite coin electrode anchored with Fe-Pd nanoflakes with excellent mechanicalstrength is introduced as an excellent electrocatalyst for oxygen reduction. The porous Fe۱-Pd۱NFs/graphite (porous Fe۱-Pd۱/G) coin electrode was successfully obtained via uniform dispersionof Zn powder into the matrix of commercial graphite powder (۹۸%), pressing under optimizedpressure followed by treatment in H۲SO۴ solution containing Fe۲+ and Pd۲+ cations, leading to partial leaching out of Zn from graphite matrix as well as partial electroless substitution of Fe-Pd nanoflakes with Zn metal. At present, due to limited energy resources, limited fossil fuels and environmental problems caused by pollutants, the use of new energy sources and conversion methods with higher efficiency has become more and more attention of researchers[۱]. In thisregard, the use of fuel cells has been one of the efforts of researchers to overcome theseproblems. Fuel cells can be a good alternative to limited oil and gas resources and batteries due totheir renewability and availability; because, like batteries, they convert chemical energy intoelectricity, and like a combustion engine, they convert fuel and oxidant into electrical energy; atthe same time, they also eliminate their disadvantages[۲].Oxygen reduction reaction (ORR) for use in fuel cell cathodes has also been the subject of extensive research over the past century. This is mainly due to the oxygen reduction reaction for energy conversion, especially in the fields of fuel cells and metal batteries - Air is very important.To prepare the porous Fe۱-Pd۱/G electrocatalyst, a mixture of ۰.۰۲ M of Fe۳O۴ and ۰.۰۰۵ M of PdCl۲ was prepared in HCl solution and for the first ۰.۵ hours in the bath. Was placed to disperse the particles in the solution evenly in the nanoscale. Then, in order to deposit iron and palladium on the surface of the graphite coin, the prepared porous tablets were placed separately in theprepared solutions for ۱.۵ hours. Then, to remove chemical residues adhering to the electrode *surface, it was washed with distilled water. Finally, the tablets were placed in room air for ۱ hour to prepare for electrochemical experiments.Figure ۱ shows the results of cyclic voltammetry test in saturated nitrogen and saturated oxygenmedium. Due to the shape in the oxygen saturation medium, the reduction of oxygen reductionby the electrocatalyst Porous Fe۱-Pd۱/G in the potential range of (-۰.۵) Volt appears as PdO.However, by injecting nitrogen into the electrolyte at ۵, ۱۰, ۱۵, ۲۰ and ۳۰ minutes, the peak flow related to oxygen reduction has decreased. In the oxygen saturation environment, we see a decrease in the return voltage from zero to -۱, which according to previous studies, the peak ofthe oxygen reduction reaction occurs in this interval. As a result, this peak is related to the oxygen reduction reaction. The presence of the oxygen reduction reaction peak reminds us that the Porous Fe۱-Pd۱/G electrocatalyst can be used as an oxygen reduction reaction catalyst[۳].The porous Fe-Pd NFs/graphite coin was prepared using facile electroless deposition of Fe-Pdnanoflakes onto porous Zn-graphite coin obtained from pressed commercial graphite and Znpowders. This research opens up new opportunities for facile and low-cost preparation of binary or ternary nanocomposites containing various metals for fuel cell and biosensor applications

کلیدواژه ها:

Fe-Pd nanoflakes ، oxygen reduction ، electrochemical impedance spectroscopy ، Nano Catalyst.