Hydrogen/air Polymer Electrolyte Fuel Cell (PEFC) are highly attractive as energy source for mobile appli- cations, improving electrochemical kinetics rates, waste heat recovery and overcoming catalyst tolerance for reformed hydrogen at operating temperatures above 80 °C. Layered double hydroxide (LDH) nanoparticles with Mg2+/Al3+ metal cations (metal ratio 2:1) and different countervailing anions (CO2 , ClO , NO ) in the interlayer space were synthesized and tested 343 as fillers for the creation of hybrid Nafion nanocomposites using a standardized casting method. The development of such nanocomposites will lead to a highly efficient H2/air polymer electrolyte fuel cell operating at high temperatures. The produced hybrid membranes were characterized by a combination of powder X-ray diffraction, FTIR spectroscopy, and thermal analysis (DTA/TGA) that revealed the creation of homogeneous exfoliated nanocomposites. The water-transport properties were investigated by NMR spectroscopy (diffusion and relaxation time). Interlayer anions affect the lambda value (mol H2O/mol SO3H) showing better hydration with higher values compared to recast Nafion. Fuel cell tests performed in drastic conditions (1.5 abs. bar and 50% RH) at 100 °C highlighted the influence of the different interlayer anions in composite membranes. A good performance was obtained for membranes containing LDH-ClO 4 with a power density of 300 mW cm 2 at 0.6 V at 100 °C.
Investigation of layered double hydroxide (LDH) Nafion-based nanocomposite membranes for high temperature PEFCs
NICOTERA, ISABELLA;
2015-01-01
Abstract
Hydrogen/air Polymer Electrolyte Fuel Cell (PEFC) are highly attractive as energy source for mobile appli- cations, improving electrochemical kinetics rates, waste heat recovery and overcoming catalyst tolerance for reformed hydrogen at operating temperatures above 80 °C. Layered double hydroxide (LDH) nanoparticles with Mg2+/Al3+ metal cations (metal ratio 2:1) and different countervailing anions (CO2 , ClO , NO ) in the interlayer space were synthesized and tested 343 as fillers for the creation of hybrid Nafion nanocomposites using a standardized casting method. The development of such nanocomposites will lead to a highly efficient H2/air polymer electrolyte fuel cell operating at high temperatures. The produced hybrid membranes were characterized by a combination of powder X-ray diffraction, FTIR spectroscopy, and thermal analysis (DTA/TGA) that revealed the creation of homogeneous exfoliated nanocomposites. The water-transport properties were investigated by NMR spectroscopy (diffusion and relaxation time). Interlayer anions affect the lambda value (mol H2O/mol SO3H) showing better hydration with higher values compared to recast Nafion. Fuel cell tests performed in drastic conditions (1.5 abs. bar and 50% RH) at 100 °C highlighted the influence of the different interlayer anions in composite membranes. A good performance was obtained for membranes containing LDH-ClO 4 with a power density of 300 mW cm 2 at 0.6 V at 100 °C.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
