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The optimization of a novel anode for the production of hydrogen via an ammonia alkaline electrolytic cell is presented. The novel anode was prepared by electrodeposition and contains Raney nickel, platinum, and rhodium in its catalytic layer. The platinum and rhodium layers were optimized by considering their influences on reaction kinetics and characterization by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. It was demonstrated through electrochemical analysis that platinum and rhodium realized a synergistic catalytic effect on the oxidation of ammonia, showing higher activity than Pt-only electrodes with comparable catalyst loading. Hydrogen was successfully produced from a 1 M NH 3 /5 M KOH solution at 14.54 Wh/g H 2 at a current density of 2.5 mA/cm 2 by an anode containing 1 mg/cm 2 Rh and 10 mg/cm 2 Pt at ambient temperature and pressure.

The ability of planar solid oxide fuel cells ͑SOFCs͒ with lanthanum strontium vanadate ͑LSV, La 0.7 Sr 0.3 VO 3 ͒/yttria-stabilized zirconia ͑YSZ͒ and LSV/gadolinium-doped ceria ͑GDC͒ anodes to use a simulated coal syngas fuel stream containing H 2 S was investigated at 800 and 900°C. The results were compared to SOFC performance in H 2 and simulated coal syngas environments at similar temperatures. The results corroborate previous claims relating to the sulfur tolerance of LSV, as little to no decrease in performance was indicated by the voltage-current density scans or electrical impedance spectroscopy upon the injection of H 2 S into the SOFC fuel stream. The LSV/GDC-based SOFCs exhibit improved performance over LSV/YSZ-based SOFCs for all test conditions. Though it was determined that the tested LSV-based SOFCs do not reach the performance appropriate for sulfur polishing applications, LSV possesses considerable sulfur tolerance in coal syngas streams containing H 2 S; this finding indicates that LSV may have promise as an additive to Ni-based SOFC anodes to improve stability in commercial coal syngas streams.The use of gasified coal, also known as coal syngas, as a fuel for solid oxide fuel cells ͑SOFCs͒ is appealing due to its low and more stable cost compared with other proposed SOFC fuels. In June 2010, the price for northern Appalachian coal was $2.37 per million British thermal units ͑MMBtu͒, natural gas was $5.41 per MMBtu, 1 and H 2 was significantly even more expensive. Unfortunately, the presence of contaminants in coal syngas has negatively affected Nibased SOFC anodes. Most notable among these harmful substances is H 2 S, which has deactivated Ni-based SOFCs even at low concentrations. 2 Upon exposure to higher concentrations of H 2 S, Ni-based SOFC anodes exhibit irreversible poisoning. 3 With this in mind, if Ni-based SOFCs are to be fueled by coal syngas in the future, H 2 S must be removed from the fuel stream before being charged to the SOFC. This gas cleanup is currently expected to be performed by sorbents that remove H 2 S after the coal gasification process. However, it is also possible to electrochemically oxidize H 2 S directly at an SOFC anode via the reactionsThese reactions do not occur on a Ni-based SOFC anode at typical operational temperatures. However, if an alternative catalyst could cause these reactions to occur in the coal syngas stream before H 2 S reached the Ni-based SOFC, a combined SOFC process tolerant to H 2 S could possibly be realized. 4 A complication in this approach would be if SO 2 produced by the lanthanum strontium vanadate ͑LSV͒-based SOFC reverts to H 2 S in the reducing syngas environment following the SOFC outlet; operation of the SOFC at high fuel utilizations would avoid this problem by diminishing the reducing ability of the SOFC exhaust stream. An intriguing development in SOFC catalysis is the promise of using ceramic perovskites containing rare-earth materials as anode electrocatalysts. Though perovskite SOFC anodes typically exhibit decreased electro...

Large volumes of produced water with high dissolved solids content are generated by the oil and gas industry. The presence of naturally occurring radioactive materials (NORM), such as radium, in this flowback water adds to the costs associated with its handling, treatment, and disposal. In this research, clinoptilolite was tested for radium removal and its performance has been compared to that of an ion-exchange resin. Natural zeolite showed excellent stability in high chloride environments; its capacity and selectivity for radium outperformed the ion-exchange resin.

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