Iron-incorporated nickel-based materials show promise as catalysts for the oxygen evolution reaction (OER) halfreaction of water electrolysis. Nickel has also exhibited high catalytic activity for methanol oxidation, particularly when in the form of a bimetallic catalyst. In this work, bimetallic iron−nickel nanoparticles were synthesized using a multistep procedure in water under ambient conditions. When compared to monometallic iron and nickel nanoparticles, Fe−Ni nanoparticles show enhanced catalytic activity for both OER and methanol oxidation under alkaline conditions. At 1 mA/cm 2 , the overpotential for monometallic iron and nickel nanoparticles was 421 and 476 mV, respectively, while the bimetallic Fe−Ni nanoparticles had a greatly reduced overpotential of 256 mV. At 10 mA/cm 2 , bimetallic Fe−Ni nanoparticles had an overpotential of 311 mV. Spectroscopy characterization suggests that the primary phase of nickel in Fe−Ni nanoparticles is the more disordered alpha phase of nickel hydroxide.

An extensive SAXS investigation of the 3M perfluorinated sulfonic acid ionomer was performed to investigate the morphological changes that occur during and after annealing at temperatures above the T α. The effect of film thickness in the range studied, 11–45 μm, was found to be negligible. These properties were studied as a function of equivalent weight from 700 to 1100 and correlated with the water uptake as measured by dynamic vapor sorption. Isoscattering points were observed in dynamic annealing experiments of the unboiled annealed films at q = 0.023, 0.096 Å–1. On initial water uptake these films also showed isoscattering points at q = 0.024, 0.220 Å–1; q = 0.029, 0.223 Å–1; and q = 0.030, 0.211 Å–1 at 50, 80, or 95 °C, respectively, indicating a decrease in the symmetry of the scattering objects in these size regimes. Isoscattering points were absent in similar water uptake experiment for the films after boiling.

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A membrane using heterpolyacids as the protogenic group can solve the chemical durability issue of polymer electrolyte fuel cells.

Highly conducive to high conductivity: Polyoxometalates were incorporated in the backbone of a hydrocarbon polymer to produce proton-conducting films. These first-generation materials contain large, dispersed clusters of polyoxometalates. Although the morphology of these films is not yet optimal, they already demonstrate practical proton conductivities and proton diffusion within the clusters appears to be very high.

An alkaline exchange membrane (AEM) based on an aminated trimethyl poly(phenylene) is studied in detail. This article reports hydroxide ion conductivity through an in situ method that allows for a more accurate measurement. The ionic conductivities of the membrane in bromide and carbonate forms at 90 °C and 95% RH are found to be 13 and 17 mS cm−1 respectively. When exchanged with hydroxide, conductivity improved to 86 mS cm−1 under the same experimental conditions. The effect of relative humidity on water uptake and the SAXS patterns of the AEM membranes were investigated. SAXS analysis revealed a rigid aromatic structure of the AEM membrane with no microphase separation. The synthesized AEM is shown to be mechanically stable as seen from the water uptake and SAXS studies. Diffusion NMR studies demonstrated a steady state long‐range diffusion constant, D∞ of 9.8 × 10−6 cm2 s−1 after 50–100 ms. © 2012 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1743–1750, 2013

Using SAXS data, the microstructure of the ionomer formed by copolymerization of tetrafluoroethylene and CF 2 dCFO(CF 2 ) 4 SO 3 H films has been approached by two methods: a numerical method (the unified fit approach) utilizing a simple model of spherical scattering objects to determine the radius of gyration of different scattering features of the ionomer films and by a graphical method, the clipped random wave approach (CRW), using the scattering data and a porosity parameter to generate a random wave which is clipped to produce a real-space image of the microstructure. We studied films with EW of 733, 825, 900, and 1082 in both the as-cast and annealed "dry" and boiled "wet" states. The results of the two data analysis techniques are in good size agreement with each other. In addition, the CRW model show striking similarities to the structure proposed in a recent dissipative particle dynamic models. This has been the first time to our knowledge that the CRW technique has been applied to a PFSA type ionomer.

Membranes were cast from mixtures of the 3M perfluorinated sulfonic acid ionomer ͓side chain -O-͑CF 2 ͒ 4 -SO 3 H͔ and various heteropoly acids ͑HPAs͒ at a 10 or 20 wt % doping level. Membrane electrode assemblies ͑MEAs͒ fabricated from these membranes were subjected to a fuel cell testing protocol from 70 to 100°C under relatively dry conditions, dew point of 70°C, to avoid leaching of the HPA. The most significant finding was that the more stable HPAs, H 4 SiW 12 O 40 , ␣-H 3 P 2 W 18 O 62 , and H 6 P 2 W 21 O 71 , reduce the rate of F − by over half and improve the power of the MEA by 9% under these conditions. Even with the use of perfluorosulfonated ͑PFSA͒ ionomers, insufficient durability of the proton exchange membrane ͑PEM͒ in the oxidizing acidic environment of an operating PEM fuel cell continues to be a major impediment to the commercialization of these devices. The major cause of the insufficient lifetime of the PEM is thought to be oxidative degradation by hydrogen peroxide via its decomposition to hydroxyl radical. 1 Hydrogen peroxide may be present throughout the membrane electrode assembly ͑MEA͒ as it is thought to be liberated from either the anode ͑derived from crossover oxygen͒ or the cathode after a 2 e − reduction of oxygen. The hydroxyl radical is expected to be particularly damaging to the polymer, and its concentration is known to be dramatically increased by the presence of trace amounts of certain transition-metal cations such as iron, which efficiently produces hydroxyl radical from hydrogen peroxide in Fenton reagents. PEM lifetimes and functionality for operation in hotter and drier conditions may be enhanced by the addition of catalytic amounts of Pt or the cesium salt of 12-phosphotungstic acid, a heteropoly acid ͑HPA͒ that converts any permeating H 2 or O 2 in situ in the PEM into water. 2,3 It has been implied that any peroxide in the membrane is decomposed to water. Whereas improved fuel cell performance under hotter and drier operation has been demonstrated for MEAs containing membranes with these catalytic additives, little data exists to support the assumption that these same additives enhance PEM lifetime in a fuel cell.Of the additives used, the HP A are the most intriguing as they are a subset of a large class of inorganic oxides, the polyoxometalates, and only a few members of this class of compounds have been investigated as PEM additives. 4-6 The most well-known, and common, structure is the Keggin structure in which 12 metal-oxygen octahedra ͑where the metal is typically W or Mo͒ are arranged as four groups of three tetrahedrally around a central heteroatom ͑Fig. 1a͒. More complex structures, including the Dawson structure, are also illustrated in Fig. 1. 1, 2, or 3 metal-oxygen octahedra may be removed from the HPA to form the lacunary HPA. Other metal atoms can easily be substituted into the vacancies of the lacunary HPA, e.g., aluminum, allowing the HPA properties to be fine-tuned for many applications. The chemistry of HPAs and peroxides has been extensively studied...