High-temperature proton-conducting

Some researchers investigated multiphase additives. Kojima et al. [101] ball-milled MgHj with a nano-Ni/Al Oj/C composite catalyst. The mixture decomposed at a really low temperature of 200°C but in vacuum. A complex composite catalyst BCN/Ni/Pd/SWNT (where BCN is barium-calcium niobium high-temperature proton conducting compound and SWNT is single-wall-nanotubes) was also used by Yoo et al. [102] high-temperature proton conducting for ball-milled MgH. It desorbed 3 wt.%H2 in about 3,600 s at 230-250°C in vacuum. 

Iwahara, H., High temperature proton conducting oxides and their applications to solid electrolyte fuel cells and steam electrolyzer for hydrogen production. Solid State Ionics, 28/30, 573, 1988. 

I. Honma, H. Nakajima, and S. Nomura. High temperature proton conducting hybrid polymer electrol3de membranes. Solid State Ionics 154, 707-712 2002. 

M. Doyle, S.K. Choi and G. Proulx, High-temperature proton conducting membranes based on perfluorinated ionomer membrane-ionic liquid composites, J. Electrochem. Soc., 2000, 147, 34-37. 

The overall objective is to operate PEMFCs at lOO-MO C to improve CO tolerance, mitigate water and thermal management challenges and reduce membrane cost. The basic approach is to develop a composite membrane consisting of mechanical support and high-temperature proton conduction phases. In order to improve cathode performance, modification of cathode formulation and structure is on-going. Promising solid superacids are incorporated into the cathode. 

Our approach is to separate the conduction paths for H+ ions and electrons through the incorporation of a ceramic second phase. This approach essentially eliminates the combined dependence of hydrogen flux on electronic and proton conductivities. The approach is to short-circuit the electron flow-paths so that the overall flux is limited only by the proton conductivity. A similar mixed conducting requirement exists for electrodes in high-temperature proton conducting fuel cells, and some work has been carried out to develop mixed conductors as electrodes [24]. 

Somisetti, V. S. (2014). Thermal stability and ionic conductivity of high-temperature proton conducting ionic liquid Polymer Composite Electrolyte Membranes for Fuel Cell Applications. Polymer Composites for Energy Harvesting, Conversion, and Storage, vol. 1161, American Chemical Society pp. 111-126. 

Okada S, Mineshige A, Kikuchi T, Kobune M, Yazawa T (2007) Cermet-type hydrogen separation membrane obtained from fine particles of high temperature proton-conductive oxide and palladium. Thin Solid Films 515 7342-7346... 

The high temperature proton conducting oxides described here are perovskites based on SrCe03 or BaCeO in which some trivalent cations... 

Table 1. Possible applications of high temperature proton conducting solid electrolytes...

These studies on the above materials did not however, provide a direct evidence for high-temperature protonic conduction in oxide materials. A conclusive demonstration for high-temperature protonic conduction in oxides was first reported in 1981 by Iwahara et al. (1981a) for rare-earth doped perovskite oxides. 

Kokkofitis C, Ouzounidou M, Skodra A and Stoukides M (2007b), Catalytic and electrocatalytic production of H2 from the water gas shift reaction over Pd in a high temperature proton-conducting cell-reactor . Solid State Ionics, I W, 475-480. 

Langguth J, Dittmeyer R, Hofmann H and Tomandl G (1997), Studies on oxidative coupling of methane using high-temperature proton-conducting membranes ,... 

High-temperature proton-conducting membranes were obtained by strong acid treatment of the PBI... 

Hang, K. C., and Nowick, A. S. (1993). High-temperature protonic conduction in mixed perovskite ceramics. Solid State Ionics 61 77-81. 

Yang J, He R, Che Q et al (2010) A copolymer of poly[2,2 -(m-phenylene)-5,5 -bibenzimidazole] and poly(2,5-henzimidazole) for high-temperature proton-conducting membranes. Polym Int 59 1695-1700... 

Di SQ, Yan LM, Han SY et al (2012) Enhancing the high-temperature proton conductivity of phosphraic acid doped poly(2,5-benzimidazole) by preblending boron phosphate nanoparticles to the raw materials. J Power Sources 211 161-168... 

Bae J.M., Honma I., Hirakawa S. Synthesis and properties of ceramics-polymer composite membranes as high temperature proton conducting electrol)des. J. Korean Phys. Soc. 1999 35 315-319... 

Iwahara, H., and T. Hibino, 1993, New gas sensors using high temperature proton conducting ceramics, in Proc. Symp. on Chemical Sensors II, 1993, eds M. Butler, A. Ricco and N. Yamazoe (Electrochemical Society, Pennington) pp. 464-473. 

Fig. 7.16 Dependence of proton conductivity on relative humidity of a hybrid octane membrane at (a) 120°C and (b) 160°C. Reprinted with permission from Ref. [56] I. Honma, et al.. Organic/ inorganic nano-composites for high temperature proton conducting polymer electrolytes. Solid State Ionics 162-163, 237-245 (2003). Copyright Elsevier...

TanigucM, T., Morimoto, T. and Kawakado, M. (2001) High Temperature Proton Conductive Electrolyte Membrane. Patent JP2001213987A2, Toyota Central Research Development Laboratory, Inc., Japan. 

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