Progress toward Commercial Application of Electrochemical Carbon Dioxide Reduction  Chi Chen, Juliet F. Khosrowabadi Kotyk, Stafford W. Sheehan  Chem  Volume 4, Issue 11, Pages 2571-2586 (November 2018) DOI: 10.1016/j.chempr.2018.08.019 Copyright © 2018 Elsevier Inc. Terms and Conditions

Chem 2018 4, 2571-2586DOI: (10.1016/j.chempr.2018.08.019) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 1 Carbon Dioxide Conversion Strategies A schematic depicting selected (A) photochemical and photoelectrochemical, (B) biochemical, (C) thermochemical, and (D) electrochemical methods of producing syngas, alkanes, alcohols, or carboxylic acids from water and carbon dioxide. Chem 2018 4, 2571-2586DOI: (10.1016/j.chempr.2018.08.019) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 2 Standard Reduction Potentials for Small-Molecule Products These are determined from CRC Handbook data24 for selected common C1 and C2 products of CO2 reduction: carbon monoxide, formic acid, methanol, methane, formaldehyde, oxalic acid, acetic acid, ethanol, and ethylene. Chem 2018 4, 2571-2586DOI: (10.1016/j.chempr.2018.08.019) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 3 Economic Analysis for Five CO2 Electrolysis Products in Large Commodity Markets (A) 2017 US commodity price at its highest-volume purity compared with the cost of electricity for the formation of carbon monoxide,27–29 formic acid,30 methanol,31 methane,32 ethanol,26 and ethylene33 at their reversible potentials (assuming $0.05/kWh). (B) The value generated per mole of electrons consumed for each. For each case, additional risk factors based on market fluctuation, transportation cost, capital cost, and purification must also be taken into consideration. Chem 2018 4, 2571-2586DOI: (10.1016/j.chempr.2018.08.019) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 4 CO and HCOOH Production from CO2 (A) Chronological trend in current density for CO production (>1 mA cm−2) in peer-reviewed literature, as measured at atmospheric pressure in three-electrode configurations.77–100 (B) An example of gas-diffusion electrode architecture as described previously104–109 depicts one configuration for catalyst incorporation into an electrolyzer producing CO or HCOOH. Chem 2018 4, 2571-2586DOI: (10.1016/j.chempr.2018.08.019) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 5 Examples of Continuous-Flow CO2 Electrolyzers (A) Type 1, which uses a liquid feed to the cathode where CO2 is either dissolved or in ionic form. (B) Type 2, which uses a gaseous CO2 feed to the cathode while the anode is immersed in water, with either side being separated by a membrane or diaphragm. (C) Type 3, which uses gaseous inputs to both anode and cathode; predominantly high-temperature solid-oxide electrolyzers. In these cases, electrical contact is made with the electrodes through the gray flow plates. In these diagrams, endplates, gaskets, charge collectors, and bolting are omitted for simplicity. GDE, gas-diffusion electrode. Chem 2018 4, 2571-2586DOI: (10.1016/j.chempr.2018.08.019) Copyright © 2018 Elsevier Inc. Terms and Conditions