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CO2 - Loop for Energy storage and conversion to Organic chemistry Processes through advanced catalytic Systems

European Union Seventh Framework Programme
Focus on electro-catalytic reduction of carbon dioxide
 Home Newsletter 4 / March 2015
 

CEOPS upcoming events:

The CEOPS project will held 2 events in the frame of the upcoming E-MRS Spring Meeting 2015 at the Grand Palais in Lille, France.

 

Photo Summer School

  • Register now to CEOPS 1st Summer School !

This one day school on Carbon dioxyde recovery will be held on 10 May 2015, aiming for fruitful exchanges between students and teachers. 
The event is open to all categories of students, from Master to Post-docs. A financial support to attend the school is available. 

Further information and the full programme are available here


Register before 30 April 2015 here

 

Photo WS Lille

  • Participate in the 2nd CEOPS workshop !

The 2nd CEOPS workshop, entitled "Carbon dioxide recovery and circular economy of carbon" will be held on 11 May 2015.
Scope of this one day symposium (combined with symposium A: Materials, mechanisms and devices in nano energy) is to discuss the current R&D situation, especially by considering the materials aspects in our E4F model for a future sustainable energy supply for the whole world. 

Further information and the full programme are available here 

 

Project coordinator:

Laurent BEDEL
CEA-Grenoble - LITEN-DTBH
38054 Grenoble Cedex 9
France
Tél: 33-4-38-78-57-20
laurent.bedel@cea.fr

 

 

Carbon dioxide emitted in the combustion of fossil fuels is a waste, but it can also be seen as a valuable resource. The CEOPS project is focused on the development of advanced catalysts and processes for the conversion of CO2 to methane (pathway A), at the point of CO2 emission, and, after methane transportation, the direct conversion of methane to methanol (pathway B), at the final user facilities. Methane can be used as an easily storable and transportable carbon vector, which can be injected into the existing natural gas network. 
CEOPS develops and evaluates three different processes for the direct conversion of CO2 into methane: DBD (Dielectric Barrier Discharge) plasma catalysis, Photo-activated catalysis and Electro-catalytic reduction.
The electro-catalytic reduction process tries to electrically reverse the methane combustion reaction (I) :

CH4 + 2O2 --> CO2 + 2 H2O (I) 

I
f renewable electrical energy from intermittent sources is used to promote the reverse reaction, the produced methane may be seen as a solution for electricity storage. This reaction can proceed in an electrolytic cell, where the cathodic reaction (II) is the conversion of carbon dioxide to methane. The catalytic cathode is designed and supplied by OMNIDEA, and is coupled to the anode, where water oxidation (III) takes place, with O2 evolution:

CO2 + 8H+ + 8e- --> CH4 + 2H2O (II) 4H2O --> 2O2 + 8H+ + 8e- (III) 

One of the novelties of the CEOPS project is the use of room temperature ionic liquids as electrolytes. These substances are molten salts with low melting points, which combine high electrical conductivity with high CO2 solubility. This process has been implemented and evaluated in an electrochemical reactor at NOVA.

 

Experimental set-up

Preliminary experiments were performed in a high-pressure, single compartment electrochemical reactor of 150 cm3 volume. Zinc was used as sacrificial anode. In this experimental set-up, electrolysis can be carried-out at pressures from atmospheric pressure up to 100 bar, and from room temperature up to 80ºC. After electrolysis, the gaseous samples were analysed by gas chromatography equipped with a TCD detector. Simultaneously with these experiments, a high-pressure, two compartment electrochemical reactor of 1800 cm3 volume was designed, and built. It is currently under testing. In this reactor the two compartments are separated by a Nafion membrane. The reactor is also equipped with inlet and outlet ports to allow recirculation of electrolyte coupled to a recirculation pump. Several ionic liquids of the imidazolium family are being tested. The first tests were carried out with 1-butyl-3-methyl-imidazolium tetrafluoroborate.

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Electro-reduction catalysts

Earlier studies in aqueous electrolytes had indicated that copper has unique properties for converting CO2 into hydrocarbons. Recently, it was shown that, contrarily to what was previously believed, other transition metals, such as Au, Ag, Pt, Ni, Zn, Fe, could also produce methane and methanol from CO2 at their surface, although at low rate. Micro/nanostructured copper based catalysts were developed containing particles of other transition metals such as nickel and zinc. It is envisaged through these bifunctional catalysts to be able to control the extent of hydrogen evolution and CO2 reduction at the surface of the cathode to tune the selectivity of the electrochemical reaction.

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Results

- Several of the parameters investigated have a drastic effect in the selectivity and faradaic efficiencies of CO2 reduction, namely, voltage applied, CO2 pressure and the catalytic couple cathode material/ionic liquid based electrolyte.
- By controlling the above mentioned parameters it is possible to tune the electrochemical reaction to produce only hydrogen, a mixture of CO and hydrogen and only CO with a selectivity close to 1 and faradaic efficiencies close to 100%.
- Methane was frequently detected as a reaction product, but in highly variable yields . In some cases, high faradaic efficiencies (>40%) and selectivities were obtained. The influence of impurities in the used electrolytes is currently under study.

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