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Metal nanoparticles are of significant importance for chemical and electrochemical transformations due to their high surface-to-volume ratio and possible unique catalytic properties. However, the poor thermal stability of nano-sized particles typically limits their use to low temperature conditions (<500 C).Furthermore, for electrocatalytic applications they must be placed in simultaneous contact with percolating ionic and electronic current transport pathways. Broader contextSolid oxide fuel cells (SOFCs) provide unparalleled fuel-to-electric conversion efficiency across power scales, from a few milliwatts to hundreds of megawatts. A key barrier to widespread SOFC deployment has been high cost, in part attributable to the high temperature of operation, typically in the 800-1000 C range.Lower temperature operation, in turn, has been hindered by poor electrocatalysis rates. Here we demonstrate SOFC anodes with unprecedented activity for both hydrogen and methane electro-oxidation at 600 C. The innovation lies in the use of nanostructured ceria in combination with ultra-low loadings (11 mg cm À2 ) of catalytic metals: Pt, Pd, Ni or Co. Despite the nanoscale features, the activity experiences negligible degradation over a continuous measurement period of 120 h. This work sets the stage for the adoption of high efficiency SOFCs for the cost-effective utilization of natural gas in electric power generation.

A pulse electrodeposition method of preparing thin platinum catalyst layers for polymer electrolyte membrane fuel cell ͑PEMFC͒ cathodes has been developed through surface activation of the gas diffusion layer ͑GDL͒ by a wetting agent. The performance of the catalyst layer was optimized by wetting agent type, immersion time in the wetting agent, and pulse deposition parameters such as total charge density, peak current density, and duty cycle ratio. The T off time played a more important role than the T on time in determining the electrode characteristics such as high concentration of Pt, smaller particle size, and loading. Pt cathodes prepared using a peak current density of 400 mA/cm 2 with a duty cycle of 10.7% and total charge density of 6 C/cm 2 resulted in a thin platinum catalyst layer ͑1.92 m͒ and uniformly distributed platinum nanoparticles ͑3-4 nm͒ on the GDL surface. Novel cathodes with Pt loading of 0.33 mg/cm 2 prepared in the present study exhibited 746 mA/cm 2 at 0.7 V.

Nano-precipitates of Sm-doped CeO2 were uniformly coated onto porous Pt thin films via cathodic electrochemical deposition. Deposition of only 5 min created an oxide coating that increased the values of the electrode conductance by more than two orders of magnitude and provided outstanding thermal stability even at 600 °C for more than 100 h compared to the bare Pt electrodes.

No abstract

Highly porous SnO2 fiber-in-tubes (FITs), which are functionalized with perovskite La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCM) particles as a chemical sensitizer, are used as a superior formaldehyde sensing layer.

Cathodic electrochemical deposition-treated silver cathodes for solid oxide fuel cell achieved 40% enhanced peak power density and 50 hour thermal stability.

It is shown that an electrochemically‐driven oxide overcoating substantially improves the performance of metal electrodes in high‐temperature electrochemical applications. As a case study, Pt thin films are overcoated with (Pr,Ce)O2−δ (PCO) by means of a cathodic electrochemical deposition process that produces nanostructured oxide layers with a high specific surface area and uniform metal coverage and then the coated films are examined as an O2‐electrode for thin‐film‐based solid oxide fuel cells. The combination of excellent conductivity, reactivity, and durability of PCO dramatically improves the oxygen reduction reaction rate while maintaining the nanoscale architecture of PCO layers and thus the performance of the PCO‐coated Pt thin‐film electrodes at high temperatures. As a result, with an oxide coating step lasting only 5 min, the electrode resistance is successfully reduced by more than 1000 times at 500 °C in air. These observations provide a new direction for the design of high‐performance electrodes for high‐temperature electrochemical cells.