Electrochemical study of temperature and Nafion effects on interface property for oxygen reduction reaction

Abstract

With the growth of new energy economy, proton exchange membrane fuel cell (PEMFC) has great potential to be success. However, the lack of high-performance catalyst layer (CL) especially at cathode limits its applications. It is becoming increasingly important to understand interface property during electrocatalytic oxygen reduction reaction (ORR). Here, the rotating disk electrode (RDE) method is developed to study the temperature and Nafion ionomer content effects on interface formed between Nafion and Pt/C. The results show that the temperature has the significant influence on electrochemical active sites, charging double capacitance, and reaction polarization resistance at low Nafion content region. Excess Nafion loaded in CLs will turn to self-reunion and increase the exposed active sites. We find that the optimum Nafion loading is in the range of 30 to 40 wt.%. The highest specific activity we achieve is 107.8 μA/cm 2 .Pt at 60°C with 0.4 of ionomer/catalyst weight ratio, corresponding to the kinetic current 283.5 μA at 0.9 V. This finding provides new insights into enhancing the Pt utilization and designing high-efficiency catalysts for ORR.

Microfabrication atomic layer deposited Pt NPs/TiN thin film on silicon as a nanostructure signal Transducer: Electrochemical characterization toward neurotransmitter sensing

“…One can conclude this redox peak is related to Pt NPs electrooxidation. Nafion film can act as a protective layer that causes to cover of the Pt NPs activity [60,61]. It can also be observed from Fig.…”

Fuel Cells as a Source of Green Energy

“…The commercial name of Teflon based polymer electrolyte is Nafion [20]. It has a high ionic conductivity at 80°C, good thermal and chemical stability [24][25][26][27], and high chemical resistance. Its chemical chain is shown in Figure 5 [28].…”

Oxygen Absorption in Electrocatalyst Layers Detected by Scanning Electrochemical Microscopy

“…Nafion ionomer exhibits a self‐assembly behavior in aqueous solutions [16–18] . This self‐assembly, on the catalyst layers of PEMFC electrodes, ensures sufficient ionic conductivity when the optimum amount of ionomer is present [19–21] . The properties, structure, and behavior of a self‐assembled thin layer of Nafion on various substrates has also been investigated in detail [19,22–25] .…”

“…[ 16 , 17 , 18 ] This self‐assembly, on the catalyst layers of PEMFC electrodes, ensures sufficient ionic conductivity when the optimum amount of ionomer is present. [ 19 , 20 , 21 ] The properties, structure, and behavior of a self‐assembled thin layer of Nafion on various substrates has also been investigated in detail. [ 19 , 22 , 23 , 24 , 25 ] Chlistunoff and Sansiñena[ 22 , 26 , 27 ] published a series of contributions on ORR taking place on carbon‐supported catalysts in which they placed great emphasis on the role of Nafion self‐assembly by means of cyclic voltammetry and rotating ring disc electrode (RRDE) methods in an aqueous media.…”