PRODUCTION OF METHANE AND ETHYLENE IN ELECTROCHEMICAL REDUCTION OF CARBON DIOXIDE AT COPPER ELECTRODE IN AQUEOUS HYDROGENCARBONATE SOLUTION

The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher value products. Herein, we describe the use of porous copper electrodes to catalyze the reduction of carbon dioxide into higher value products such as ethylene, ethanol and, notably, propanol. For n-propanol production, faradaic efficiencies reach 4.93% at -0.83 V vs RHE, with a geometric partial current density of -1.85 mA/cm2. We have documented the performance of the catalyst in both pristine and urea-modified foams pre- and post-electrolysis. Before electrolysis, the copper electrode consisted of a mixture of cuboctahedra and dendrites. After 35-minute electrolysis, the cuboctahedra and dendrites have undergone structural rearrangement. Changes in the interaction of urea with the catalyst surface have also been observed. These transformations were characterized ex-situ using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. We found that alterations in the morphology, crystallinity, and surface composition of the catalyst led to the deactivation of the copper foams.

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Photochemical and Electrochemical Reduction of Carbon Dioxide Catalyzed by a Polyoxometalate-Organic Photosensitizer Complex

10.26434/chemrxiv.7177892 ◽

2018 ◽

Author(s):

Chandan Dey ◽

Ronny Neumann

Keyword(s):

Carbon Dioxide ◽

Cyclic Voltammetry ◽

Formic Acid ◽

Electrochemical Reduction ◽

Mass Spectroscopy ◽

Photochemical Reactions ◽

Reducing Agent ◽

Covalent Attachment ◽

Hybrid Complex ◽

Open Face

A manganese substituted Anderson type polyoxometalate, [MnMo6O24]9-, tethered with an anthracene photosensitizer was prepared and used as catalyst for CO2 reduction. The polyoxometalate-photosensitizer hybrid complex, obtained by covalent attachment of the sensitizer to only one face of the planar polyoxometalate, was characterized by NMR, IR and mass spectroscopy. Cyclic voltammetry measurements show a catalytic response for the reduction of carbon dioxide, thereby suggesting catalysis at the manganese site on the open face of the polyoxometalate. Controlled potentiometric electrolysis showed the reduction of CO2 to CO with a TOF of ~15 sec-1. Further photochemical reactions showed that the polyoxometalate-anthracene hybrid complex was active for the reduction of CO2 to yield formic acid and/or CO in varying amounts dependent on the reducing agent used. Control experiments showed that the attachment of the photosensitizer to [MnMo6O24]9- is necessary for photocatalysis.<div> </div>

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Investigation into the Re-Arrangement of Copper Foams Pre- and Post-CO2 Electrocatalysis

Chemistry ◽

10.3390/chemistry3030048 ◽

2021 ◽

Vol 3 (3) ◽

pp. 687-703

Author(s):

Jennifer A. Rudd ◽

Sandra Hernandez-Aldave ◽

Ewa Kazimierska ◽

Louise B. Hamdy ◽

Odin J. E. Bain ◽

...

Keyword(s):

Crystal Structure ◽

Carbon Dioxide ◽

Carbon Capture ◽

Surface Composition ◽

Structural Rearrangement ◽

Copper Electrode ◽

Copper Electrodes ◽

Porous Copper ◽

Chemical Products ◽

Co2 Electrolysis

The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher-value chemical products. Herein, we fabricated a porous copper electrode capable of catalyzing the reduction of carbon dioxide into higher-value products, such as ethylene, ethanol and propanol. We investigated the formation of the foams under different conditions, not only analyzing their morphological and crystal structure, but also documenting their performance as a catalyst. In particular, we studied the response of the foams to CO2 electrolysis, including the effect of urea as a potential additive to enhance CO2 catalysis. Before electrolysis, the pristine and urea-modified foam copper electrodes consisted of a mixture of cuboctahedra and dendrites. After 35 min of electrolysis, the cuboctahedra and dendrites underwent structural rearrangement affecting catalysis performance. We found that alterations in the morphology, crystallinity and surface composition of the catalyst were conducive to the deactivation of the copper foams.

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