Catalyst supports membranes

The establishment of AST protocols will provide a standard set of test conditions and operating procedures for evaluating new cell component materials and stmctures. The present AST protocols developed individually by DOE and USFCC are still limited to the component level (electrocatalyst, catalyst support, membrane, and MEA). It is worth noting that, even though these two protocols generally agree with each other, they still differ in a few areas. Achieving the completion and unanimity of AST protocols for the PEM fuel cell as a whole, in addition to those for the components, is imperative for the near future. 

It was demonstrated that MWNT/PVA aerogels exhibit interesting thermal and catalytic properties as well as absorption capacity of polycyclic aromatic substances and can be applied as catalyst supports, membranes, and thermal conductors. 

Monofunctional organosilanes terminating the surfaces of porous xerogels or coatings can be used as catalyst supports, membranes, or sensors [241]. For example, Fig. 16a shows that incorporation of aminosilanes in a porous silicate coating results in significant COj adsorption, despite rather low surface areas. In order to reduce the influence of water vapor, hydro-phobic components can be incorporated. Figure 16b shows the effect of a propylsilane addition on the water uptake of an aminosilane-silicate film. 

Halonen N, Rautio A, Leino A-R, KyUonen T, Toth G, Lappalainen J, Kordas K, Huuhtanen M, Keiski R L, Sdpi A, Szabo M, Kukovecz A, Konya Z, Kiricsi I, Ajayan P M, Vajtai, R (2010) Three-dimensional carbon nanotube scaffolds as particulate filters and catalyst support membranes. ACS Nano, 4,2003-2008... 

Kawasaki et /. (1996) have used a supported membrane catalyst for extraction of erythromycin from its dilute, slightly alkaline aqueous solutions. 1-Decanol was used as an intermediate fluid membrane phase and a buffered acidic aqueous solution was used to strip the organic membrane. 

Wang X, Li WZ, Chen ZW, Waje M, Yan YS. 2006. Durability investigation of carbon nanotube as catalyst support for proton exchange membrane fuel cell. J Power Sources 158 154-159. 

Another way of retaining the catalyst is to create dendrimer-supported ligands, thereby allowing separation of the product and catalyst by membranes. Based on the readily modified BICOL backbone, two dendrimer-Hgands 43 were prepared that had performance comparable to that of MonoPhos 29 a in the hydrogenation of methyl N-acyl dehydrophenylalanine [81]. 

Janowska, I. Hajiesmaili, S. Begin, D. Keller, V. Keller, N. Ledoux, M.-J. Pham-Huu, C., Macronized aligned carbon nanotubes for use as catalyst support and ceramic nanoporous membrane template. Catal. Today 2009,145 76-84. 

M. K. Debe. Novel catalysts, catalyst supports and catalyst coated membrane methods. In Handbook of fuel cells Fundamentals, technology and applications. Vol. 3 Fuel cell technology and applications, ed. W. Vielstich, H. A. Gasteiger, and A. Lamm, 576 (2003). New York John Wiley Sons. 

Li, W, Wang, X., Chen, Z., Waje, M., and Yan, Y. Carbon nanotube film by filtration as cathode catalyst support for proton-exchange membrane fuel cell. Langmuir 2005 21 9386-9389. 

Dr. Hui has worked on various projects, including chemical sensors, solid oxide fuel cells, magnetic materials, gas separation membranes, nanostruc-tured materials, thin film fabrication, and protective coatings for metals. He has more than 80 research publications, one worldwide patent, and one U.S. patent (pending). He is currently leading and involved in several projects for the development of metal-supported solid oxide fuel cells (SOFCs), ceramic nanomaterials as catalyst supports for high-temperature PEM fuel cells, protective ceramic coatings on metallic substrates, ceramic electrode materials for batteries, and ceramic proton conductors. Dr. Hui is also an active member of the Electrochemical Society and the American Ceramic Society. 

Fumeaux, R. C., A. P. Davidson and M. D. Ball. 1987. Porous anodic aluminum oxide membrane catalyst support. European Patent Appl. 0,244,970A1. 

Irregularly hyperbranched grafts provide a useful way to modify surfaces. A variety of chemistry can be used and a wide variety of grafts can be prepared. The hyperbranched grafts can serve as supported membranes, as catalyst supports or as substrates for further covalent graft chemistry. Functional groups within these interfaces can be readily modified by solution-state chemistry. The interfaces themselves can be used as media for further chemistry within the interface or as substrates in molecular recognition and self assembly of other macromolecules. 

In this chapter, we reviewed the structure-controlled syntheses of CNFs in an attempt to offer better catalyst supports for fuel cell applications. Also, selected carbon nanofibers are used as supports for anode metal catalysts in DMFCs. The catalytic activity and the efficiency of transferring protons to ion-exchange membranes have been examined in half cells and single cells. The effects of the fiber diameter, graphene alignment and porosity on the activity of the CNF-supported catalysts have been examined in detail. 

Methanol Crossover Catalyst Performance Catalyst Fabrication Carbon Support Membrane Performance MEA Fabrication Pressurized Operation Methanol Concentration Fluid Flow Heat Transfer... 

Catalyst, Catalyst-Support, and Membrane Material Impact on Maximum Catalyst-Support Corrosion Rate Under Fully Developed H2 Starvation Conditions. Here, Advanced-Support is a Hypothetical Support with a 30-Fold Lower Corrosion Rate than Graphitized Vulcan Carbon and Membrane-X Refers to a Hypothetical Membrane with a 10-Fold Lower 02 Permeability. 

For example, POPAM dendrimers of 1,3-diaminopropane type have been used in membrane reactors as supports for palladium-phosphine complexes serving as catalysts for allylic substitution in a continuously operated chemical membrane reactor. Good recovery of the dendritic catalyst support is of advantage in the case of expensive catalyst components [9]. It is accomplished here by ultra-or nanofiltration (Fig. 8.2). 

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