Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters








Database
Language
Publication year range
1.
Science ; 337(6095): 713-7, 2012 Aug 10.
Article in English | MEDLINE | ID: mdl-22879514

ABSTRACT

There is a critical need for improved methane-oxidation catalysts to both reduce emissions of methane, a greenhouse gas, and improve the performance of gas turbines. However, materials that are currently available either have low activity below 400°C or are unstable at higher temperatures. Here, we describe a supramolecular approach in which single units composed of a palladium (Pd) core and a ceria (CeO(2)) shell are preorganized in solution and then homogeneously deposited onto a modified hydrophobic alumina. Electron microscopy and other structural methods revealed that the Pd cores remained isolated even after heating the catalyst to 850°C. Enhanced metal-support interactions led to exceptionally high methane oxidation, with complete conversion below 400°C and outstanding thermal stability under demanding conditions.

2.
Article in English | MEDLINE | ID: mdl-22432608

ABSTRACT

Solid oxide fuel cells (SOFCs) and solid oxide electrolyzers (SOEs) hold much promise as highly efficient devices for the direct interconversion of chemical and electrical energy. Commercial application of these devices, however, requires further improvements in their performance and stability. Because the performance of SOFC and SOE electrodes depends on their microstructures, electronic and ionic conductivities, and chemical reactivities, the needed improvements require the expertise of various disciplines, with catalytic science playing an important role. Highly active and thermally stable catalysts are required to limit the internal losses in the devices, increase the range of fuels they can use, and decrease the temperatures at which they operate. In this article we review some of the most important recent advances in catalysis for SOFC and SOE electrodes and highlight additional improvements that are needed.


Subject(s)
Electric Power Supplies , Electrochemistry/instrumentation , Oxides/chemistry , Catalysis , Ceramics/chemistry , Copper/chemistry , Electrochemistry/methods , Electrodes , Nickel/chemistry
3.
Nat Mater ; 3(1): 17-27, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14704781

ABSTRACT

Fuel cells will undoubtedly find widespread use in this new millennium in the conversion of chemical to electrical energy, as they offer very high efficiencies and have unique scalability in electricity-generation applications. The solid-oxide fuel cell (SOFC) is one of the most exciting of these energy technologies; it is an all-ceramic device that operates at temperatures in the range 500-1,000 degrees C. The SOFC offers certain advantages over lower temperature fuel cells, notably its ability to use carbon monoxide as a fuel rather than being poisoned by it, and the availability of high-grade exhaust heat for combined heat and power, or combined cycle gas-turbine applications. Although cost is clearly the most important barrier to widespread SOFC implementation, perhaps the most important technical barriers currently being addressed relate to the electrodes, particularly the fuel electrode or anode. In terms of mitigating global warming, the ability of the SOFC to use commonly available fuels at high efficiency, promises an effective and early reduction in carbon dioxide emissions, and hence is one of the lead new technologies for improving the environment. Here, we discuss recent developments of SOFC fuel electrodes that will enable the better use of readily available fuels.


Subject(s)
Ceramics/chemistry , Electric Power Supplies/trends , Electrochemistry/instrumentation , Electrochemistry/methods , Electrodes , Energy Transfer , Hydrogen/chemistry , Metals/chemistry , Temperature , Conservation of Natural Resources/trends , Electrochemistry/trends
4.
Chem Commun (Camb) ; (22): 2334-5, 2001 Nov 21.
Article in English | MEDLINE | ID: mdl-12240062

ABSTRACT

Solid-oxide fuel cells with Cu-ceria anodes are shown to provide stable power generation through the direct oxidation of hydrocarbon fuels having sulfur levels similar to that in gasoline and can be regenerated by steam after being poisoned with higher sulfur levels.


Subject(s)
Bioelectric Energy Sources , Fossil Fuels , Electrochemistry , Oxygen/chemistry , Sulfur/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL