Electrochemical reduction of CO2 at copper nanofoams
This invention includes a catalytic copper electrode is selected from the group comprising copper nanofoam, copper aerogel, and copper nanoparticles. Particular note is made of the catalytic copper electrode having at least about 5 times and preferably about 10 times the electrochemically accessible surface area as determined by the Randles-Sevcik equation at 50 mV/s. particular note is made of the catalytic coper electrode being a copper nanofoam electrode. This invention further includes a method for the reduction of CO 2 by the steps of (i) providing a membrane divided electrochemical cell comprising an anode in a first cell compartment, a catalytic-copper electrode in a second cell compartment containing an aqueous electrolyte in contact with the anode and cathode; (ii) introducing CO 2 to said second cell compartment (iii) exposing said CO 2 to said catalytic-copper electrode at a step potential between about −0.8 and preferably about −1.0 and about −1.8 V versus the reference electrode; (iv) electrochemically reducing said CO 2 and solution by the catalytic-copper electrode in the second cell compartment; (v) thereby producing propylene and (vi) extracting said propylene from said second compartment.
1. An electrochemical cell for producing formic acid comprising a catalytic copper electrode selected from the group comprising copper nanofoam, copper aerogel, and copper nanoparticles having a faradaic efficiency in producing formic acid of at least about 26%, the catalytic copper electrode having at least about 5 times the electrochemically accessible surface area as determined by the Randles-Sevcik equation at 50 mV/s.
2. The electrochemical cell of claim 1 , wherein said catalytic copper electrode has at least about 10 times the electrochemically accessible surface area as determined by the Randles-Sevcik equation at 50 mV/s.
3. The electrochemical cell of claim 1 , wherein said catalytic copper electrode is a copper nanofoam electrode.
4. A method for the reduction of CO 2 by the steps of
(a) providing a membrane divided electrochemical cell comprising an anode in a first cell compartment, a catalytic-copper electrode in a second cell compartment containing an aqueous electrolyte in contact with the anode and catalytic-copper electrode, wherein said catalytic copper electrode is selected from the group comprising copper nanofoam, copper aerogel, and coper nanoparticles, wherein said catalytic-copper electrode has at least about 5 times the electrochemically accessible surface area as determined by the Randles-Sevcik equation at 50 mV/s;
(b) introducing CO 2 to said second cell compartment;
(c) exposing said CO 2 to said catalytic-copper electrode at a step potential between about −0.8 and about −1.1 V versus the reference electrode;
(d) electrochemically reducing said CO 2 and solution by the catalytic-copper electrode in the second cell compartment;
(e) thereby producing formic acid; and,
(f) extracting said formic acid from said second compartment.
5. The method of claim 4 wherein said electrolyte is KHCO 3 .
6. The method or claim 4 wherein said electrolyte is about 0.5 M to about 0.1 M.
7. The method of claim 4 wherein said (e) producing of formic acid is at a faradaic efficiency of at least about 26%.