Nickel oxide false(normalNiOfalse) cathode solubility in the molten carbonate fuel cell (MCFC) electrolyte has been identified as one of the major technical obstacles facing fuel cell commercialization. The solubility of transition metal oxides is thought to be a function of the acid/base chemistry of the melt, controlled by the CO2 partial pressure of the oxidant gas. In this study, equilibrium nickel oxide solubility experiments were performed in a molten Li2CO3‐K2CO3 mix under various gas compositions to identify the conditions of minimum solubility. An analytical procedure is presented in which the dissolved nickel ions are isolated from the frozen electrolyte and spectrometrically analyzed to a detection limit of 0.5 ppm (μg Ni/g electrolyte). Under current MCFC operating conditions, the CO2 partial pressure is such that normalNiO cathode solubility is found to occur under acidic dissolution conditions. For a given gas atmosphere, it is shown that normalNiO solubility can be reduced by the addition of small amounts of basic alkaline earth oxides to the acidic electrolyte. The addition of 1 weight percent normalSrO resulted in a fifteenfold decrease in the dissolved normalNiO concentration.

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Catalytically grown carbon nanofibers are a set of novel structures that are produced by the decomposition of selected carbon-containing gases over metal particles. These conformations consist of nanosized graphite platelets separated a distance of at least 0.34 nm and stacked in various orientations with respect to the fiber axis. Such an arrangement results in a unique structure that is composed of an infinite number of extremely short and narrow pores, suitable for the sequestering of small molecules. We have attempted to capitalize on this blend of properties by using such structures for the selective removal of organic contaminants from aqueous streams. Experimental results indicate that nanofibers possessing a structure in which the graphite platelets are aligned perpendicular to the fiber axis and possessing a high degree of structural perfection exhibit superior selective adsorption properties with respect to removal of alcohols from aqueous media over those displayed by active carbon. Adsorption was enhanced when the carbon nanofibers were initially subjected to a treatment in 1 M hydrochloric acid. In contrast, when this step was carried out in the presence of 1 M nitric acid, the beneficial properties of the nanofibers were effectively suppressed. An analogous series of experiments carried out with nanofibers possessing a structure in which the graphene layers were oriented at an angle with respect to the fiber axis did not result in the same degree of selective capture of the alcohols. A rationale is presented to account for this diverse pattern of behavior.

Both natural and polluting metal ions are taken up by marine organisms. For many metal, and metal-containing ions, mechanisms exist which allow these organisms to discriminate between essential and non-essential ions, and reject the latter. In this article we examine the accumulation mechanisms and effects of metal and metal-containing ions on bivalve molluscs and tunicates (sea squirts). Special emphasis is put on the internal or physiological environment of metal ions in marine organisms. A molecular mechanism based on experimental studies is presented to explain the extraordinary accumulation of vanadium in tunicate blood cells called vanadocytes. Vanadium in the form of vanadate anion is transported into the blood cells by passage through anionic channels. Inside the cell it is reduced to cationic V (III) and V (IV) ions which are trapped inside.

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