Study of the preparation and property of oxygen reduction electrode based on polyaniline or polypyrrole

Polyaniline (PAM) and polypyrrole (PPy) is developed rapidly with special physical and chemical performance. According to high catalytic activity, polyaniline is applied in a wide range of electrocatalysis area, especially for oxygen reduction. In this paper, electrochemical prepared polyaniline was used as catalyst as well as the loading of noble metal catalyst for manufacturing oxygen reduction electrode. Then the influence of carrier, noble metal and their binding forms to the ability of oxygen reduction were investigated by cyclic voltammeter. The result shows that PANT carrier was the most influential factor for oxygen reduction; for single noble metal catalyst, Pt shows bigger catalytic activity than Ag. And the best catalytic activity was optimized at dual deposited catalyst as Ag, Pt mass ratio to 23:100. Further more; compared to glassy carbon, graphite is much better for electrode basement. Air cathode is widely used as the positive electrode of fuel cell and metal air battery as well as cathode of electrochemical reactor, such as H2O2 generator, electrochemical oxygen generator([1-3]). It can be used as Chlorine alkali industry electrode also. The electro catalyst of cathode is different in various application fields. The oxygen reduction reaction (ORR)([4, 5]) is the most important reaction for air cathode. Normally, the air electrode used in fuel cell and metal air battery is made of carbon carrier on which sufficient amount of highly dispersed electrode catalysts are supported. There is different catalysts for ORR, such as graphite and multiple carbon, aurum, hydrargyrum, nickel oxide, transition metal macro cyclic complex compounds, platinum(Pt) group of metals and alloy, silver(Ag), palladium metal, etc. The performance of air cathode is related not only to the activity and amount of the electro catalyst, but also to the ratio of the electrode component in the mixture. The pore diameter and surface structure of the cathode will change with the reaction time, and the change will influence the oxygen reduction process. For easy synthesization, character stability, and contains a large number of the electrical active redox or chemical activity, conductive polymers can be used as electro catalytic, electro chromic devices, electrochemical sensors, metal corrosion, etc. Polyaniline (PAN) and polypyrrole (PPY) modified electrode is most commonly used as the catalyst and its carrier for ORR[6-8]. In which, the electrode prepared form composite deposition of noble metals on/in conductive polymer is promising. The methods of linear polarization, cyclic voltammetery (CV), rotating ring disk electrode (RRDE), electrochemical impedance spectroscopy (EIS), etc, provide a plenty of information for study on the reaction dynamics of electrode([9]) In this paper, electrochemical prepared polyaniline was used as catalyst as well as the loading of noble metal catalyst for manufacturing oxygen reduction electrode. Then the influence of carrier, noble metal and their binding forms to ability of oxygen reduction were investigated by cyclic voltammeter to optimize a conductive loaded composite deposited catalyst system.