Nafion/Acid Functionalized Zeolite Beta Nanocomposite Membrane for High Temperature Pemfcs
Zhongwei Chen1, Brett A. Holmberg1, Wenzhen Li2, Xin Wang3, Ronnie A. Munoz Jr.2, and Yushan Yan2. (1) University of California, Riverside, A242 Bourns Hall, Chemical Engineering, Riverside, CA 92507, (2) Chemical and Environmental Engineering, University of California, Riverside, Bourns Hall A242, Riverside, CA 92521, (3) Department of Chemical and Environmental Engineering, University of California, Riverside, Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92507
Nafion/Acid Functionalized Zeolite Beta (NAFB) nanocomposite membrane has been successfully prepared by in situ hydrothermal crystallization method. The Acid Functionalized Zeolite Beta (AFB) nanocrystals less than 20 nm were formed and embedded into the Nafion matrix. The physico-chemical properties of all membranes were investigated regarding their tensile strength, water uptake and thermogravimetric analyzer (TGA). The proton conductivity commercial Nafion membrane and the NAFB composite membrane were measured with different relative humidity (RH) at 25, 80, 120 oC. Compared with commercial Nafion membrane, the NAFB composite membrane has much higher proton conductivity at 120 oC and reduced RH. NAFB composite membrane and commercial Nafion membranes were also studied in an H2/O2 PEMFC over a wide range of RH values from 25 to 100% at temperatures of 80 and 120°C. The NAFB composite membrane showed a pronounced improvement over commercial Nafion membranes when operated at 120 °C and reduced RH. The high performance of the NAFB composite membranes at low RH was attributed to improved water retention due to the presence of absorbed water species within the pores and on the surface of AFB. NAFB composite membranes have the potential for use with high temperature PEMFC.