Effect of reduced graphene oxide (rGO) in chitosan/Pahae natural zeolite-based polymer electrolyte membranes for direct methanol fuel cell (DMFC) applications

Abstract

The use of electrolyte membranes for fuel cell applications has grown rapidly, and one of the materials often developed is chitosan. In this study, polymer electrolyte membranes were successfully produced using chitosan and Pahae natural zeolite with the addition of various reduced Graphene Oxide (rGO) concentrations. Furthermore, water and methanol uptake values, methanol permeability, ion exchange capacity, and proton conductivity were the basic characteristics of Direct Methanol Fuel Cells (DMFC) applications. The optimum water uptake value was observed in the CS/PNZ/rGO 2.0 % membrane at 294.5 %. This value increased with the addition of rGO concentration and is in line with the increasing ion exchange capacity. The CS/PNZ/rGO 2.0 % membrane has the optimum ion exchange capacity with a value of 0.8121 mmol/g. Meanwhile, the membrane permeability value tends to decrease with increasing rGO composition at each variation of methanol concentration. The proton conductivity value also increased along with rGO concentration, and the highest value was found in CS/PNZ/rGO 2.0 % at 6.777×10−6 S/cm. Based on the results, high ion exchange capacity, low permeability, and high proton conductivity indicate that CS/PNZ/rGO-based polymer electrolyte membranes can be used in Direct Methanol Fuel Cells (DMFC) applications.

Keywords

• Chitosan
• Pahae Natural Zeolite
• reduced Graphene Oxide
• Proton conductivity
• Direct Methanol Fuel Cells