The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggesstions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA, 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any oenalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. a. REPORT Fuel cells using the protic ionic liquid and rotator phase solid electrolyte principles 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: The concept of ionic liquids, formed by proton transfer from Bronsted acid to Bronsted base, serving as the proton transport media in fuel cells is evaluated at several levels. Firstly a wide range of protic ionic liquids formed from acids of a wide range of acid strengths to a variety of nitrogenic bases of different base strengths, nearly 100 in all, has been synthesized and characterized. A proton free energy level diagram, based on aqueous solution pKa data, has been developed to permit predictions of the properties of arbitrarily chosen acid-base pairs, and a modified glass electrode to directly study the proton transfer energetics, has been developed. Secondly, a class of siloxane polymers with pendant amine, or alternatively, U

The eutectic mixture of MgCl2–KCl molten salt is a high temperature heat transfer and thermal storage fluid able to be used at temperatures up to 800 °C in concentrating solar thermal power systems. The molten salt thermophysical properties are reported including vapor pressure, heat capacity, density, viscosity, thermal conductivity, and the corrosion behavior of nickel-based alloys in the molten salt corrosion at high temperatures. Correlations of the measured properties as functions of molten salt temperatures are presented for industrial applications. The test results of tensile strength of two nickel-based alloys exposed in the molten salt at a temperature of 800 °C from 1-week length to 16-week length are reported. It was found that the corrosion and strength loss is rather low when the salt is first processed to remove water and oxygen.

h i g h l i g h t sApplicability of NaCl-KCl-ZnCl 2 salts for CSP applications is evaluated. Corrosion rates are estimated by electrochemical and immersion methods. Hastelloys show corrosion rates of <10 lm/year at 800°C under anaerobic conditions. g r a p h i c a l a b s t r a c t a b s t r a c t Higher operating temperatures increase efficiency of the concentrating solar power plants but promote faster corrosion of the pipes and vessels made of Hastelloy or stainless steel materials for the moltensalt mixtures. Hastelloys C-276 and C-22 and stainless steel 304 coupons evaluated in the present study in a eutectic molten salt consisting of 13.4 mol% NaCl, 33.7 mol% KCl and 52.9 mol% ZnCl 2 showed substantially lower corrosion rates in the absence versus presence of air from 200 to 800°C as determined by electrochemical and gravimetric methods. In the presence of air, the corrosion rate for the Hastelloy C-276 in the molten salt was found to diminish with immersion time and converges around $50 lm per year after 4 weeks of immersion at 500°C, which is close to the value $40 lm per year obtained using the electrochemical method at 500°C. For anaerobic corrosion rate estimation, the corrosivity of an alloy sample was examined by immersing in molten salt inside a sealed quartz container without any contact with air, which is possible because the vapor pressure of the eutectic molten salt is only about 0.7 atm at 800°C. The corrosion rate of the Hastelloy C-276 was only 10 lm per year in the molten salt in the absence of air at 800°C, which is extremely low compared to 500 lm per year in conducting corrosion studies in the presence of air at 800°C. The Hastelloy coupons after immersion testing in the absence of air have then been examined also by SEM, and the images did not show any http://dx.

Much work has been devoted to synthesizing the non-noble metal catalyst such as nitrogen-doped carbonsupported transition metal catalysts (denoted as metal−N−C catalyst) for the oxygen reduction reaction (ORR). However, the catalytic mechanisms and precise chemical nature of the active sites in this kind of catalyst are still controversial, which hinders the development and commercialization of this novel ORR catalyst. The objective of this work is to study the nature of active sites for ORR in the Fe−N−C catalysts. We synthesized a new family of nitrogen-doped carbon with iron catalysts (denoted as Fe−N−C catalysts) by pyrolyzing the mixtures with various ratios of a nitrogen-atom rich heterocycle compound, 1-ethyl-3-methylimidazolium dicyanamide (EMIMdca), and iron chloride (FeCl 3 ). The ORR activity (J K at 0.8 V vs RHE, in 0.1 M KOH solution) of a typical catalyst, Fe 15 −N− C1000, in this family is 6.65 mA/mg, which is much higher than the values of the Fe−C (0.48 mA/mg) and N−C catalysts (0.25 mA/mg). The relationship between the ORR activity and the structures (the possible active sites in particular) of the catalysts was studied under different conditions. The active site in the catalyst is found to be the Fe−N species (most likely in the form of Fe 3 N). Metallic iron (Fe) particles, Fe 3 C species, and N−C species are not catalytically active sites, nor do these moieties interact with the Fe−N active sites during the catalysis of the ORR. High pyrolysis temperatures and increasing the Fe content during the synthesis favor the formation of the Fe−N active sites in the final catalyst. Our study opens up new synthetic control of parameters affecting the final structure and catalyst performance and allows modifying the unexplored avenues toward new multiply heteroatom doped nonprecious ORR catalysts.