Proton exchange membrane fuel cells hydrocarbon

An important possible future use for pure hydrogen is in proton-exchange-membrane fuel cells (PEMFCs) the basic source for the hydrogen could be either a hydrocarbon or an alcohol, either of which can be steam-reformed to produce water-gas.16,17 As explained above, the equilibrium concentration of carbon monoxide decreases as the temperature falls (Figure 10.1), but as little as 1% is detrimental to the operation of platinum-based catalysts in a fuel cell. Excess water, which is commonly used,18 serves to move the... 

C.H. Park, C.H. Lee, M.D. Guiver, Y.M. Lee, Sulfonated hydrocarbon membranes for medium-temperature and low-humidity proton exchange membrane fuel cells (PEMFCs). Progress in Polymer Science 2011, 36(11), 1443-1498. 

Gross M, Maier G, Fuller T, MacKinnon S and Gittleman C S (2009), Design rules for the improvement of the performance of hydrocarbon-based membranes for proton exchange membrane fuel cells (PEMFC) , in Handbook of Fuel Cells, Vol. 5 (W. Vielstich, H. Yokokawa, and H. A. Gasteiger, eds.),Wiley. 

We need to begin with end in mind road to zero-sulfur. One case which presents a great challenge to ultra-deeper desulfurization of liquid hydrocarbon fuels is the fuel processor for proton-exchange membrane fuel cells and also sohd oxide fuel cells, which require essentially near zero-sulfur fuels. 

Hydrogen as the most efficient and cleanest energy source for fuel-cell power is produced by partial oxidation followed by the water gas-shift reaction and reforming of hydrocarbons or methanol [58]. A small amount of CO (0.3-1%) in the so-produced H2 must be selectively removed because CO greatly poisons Pt/C and Pt-M/C electrocatalysts in proton-exchange-membrane (PEM) fuel cells [59, 60]. PROX of CO in excess H2 is a key reaction in the practical use of H2 in PEM fuel-cell systems. 

The bicontinuous-microemulsion polymerization technique has also been used to develop novel proton exchange membranes (PEM) for fuel cell evaluation [97]. A series of hydrocarbon-based membranes were prepared based on the formulation shown in Fig. 5, with additional ionic vinyl monomers such as VB-SLi or bis-3-sulfopropyl-itaconic acid ester. After polymerization, the membranes were treated with dilute H2SO4 (0.5 M) to convert them to PEM membranes. The good performance of these PEM membranes in a single fuel cell is illustrated in Fig. 9. 

In fuel cells systems, as reported in recent patents [13,14], membranes wUl be present not only as PEM (proton-exchange membrane), which allows protons to pass from the anode to the cathode where they are combined with oxygen and electrons to produce water, but also for the production and purification of the H2 (Figure 43.3). This system provides a C02-selective membrane process for the purification and water gas shift reaction of a reformed gas, generated from on-board reforming of a fuel, e.g., hydrocarbon, gasoline, diesel, methanol, or natural gas, to hydrogen for fuel cell vehicles. 

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