A Simple Framework for Quantifying Electrochemical CO2 Fixation Anqi Chen, Bo-Lin Lin  Joule  Volume 2, Issue 4, Pages 594-606 (April 2018) DOI: 10.1016/j.joule.2018.02.003 Copyright © 2018 Elsevier Inc. Terms and Conditions

Joule 2018 2, 594-606DOI: (10.1016/j.joule.2018.02.003) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 1 Immediate Actions Required to Substantially Abate CO2 Emissions A cartoon illustrating the competition between two potential future scenarios in determining whether the 2DT can be achieved or not for earth: actively adapting progressive strategies for emission abatements (left) and passively exhausting the remaining carbon budget in the near future (right). Joule 2018 2, 594-606DOI: (10.1016/j.joule.2018.02.003) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 2 A “Golden Triangle” to Evaluate Emission-Abating Measures (A) Emission-abating measures with high mitigation efficiency, high storage stability, and low economic cost for the “golden triangle” are ideal for large-scale deployments. (B) Comparison between carbon capture and storage (CCS). (C) Chemical fixation of CO2 (CFC). Joule 2018 2, 594-606DOI: (10.1016/j.joule.2018.02.003) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 3 Quantifying the Abatement Capability of Electrochemical Reductions of CO2 (A) A derived equation to calculate the weight of CO2 reduction for a generic full-cell electrochemical conversion of CO2 and water to a reduction product and O2 upon the consumption of 1 kWh of electric power (Equation 1). (B) The calculated values for the mitigation coefficient, σ, of various selected reduction products with corresponding n and Ecell∘. Joule 2018 2, 594-606DOI: (10.1016/j.joule.2018.02.003) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 4 Electrochemical Reduction of CO2 Driven by Fossil Fuel Power (A) State-of-the-art standard weight of CO2 emission (WCO2,emitted∘) for the generation of 1 kWh electric power via various fossil fuel power technologies, including fluidized-bed coal combustion technology (FB), subcritical coal-fire technology (Sub), integrated gasification combined cycle system (IGCC), supercritical coal-fire technology (Super), natural gas-fired combustion turbine system (NGCT), and natural gas-fired combined cycle system (NGCC). (B) Comparison between the values of σ and WCO2,emitted∘ indicating that the maximal amount of CO2 reduced via ERCs forming oxalic acid, carbon monoxide, formic acid, glyoxal, or acetic acid is greater than that emitted during power generations by several fossil fuel technologies given the same amount of electric power. (C) A plot of the energy relative to CO2 for selected chemicals along the oxidative processes of fossil fuels over their oxidation state of carbon: the arrows represent the combination of existing power generations via full combustions of fossil fuels and electrochemical reductions of CO2 (ERC) to chemicals with low relative energies. Joule 2018 2, 594-606DOI: (10.1016/j.joule.2018.02.003) Copyright © 2018 Elsevier Inc. Terms and Conditions

Figure 5 Sensitivity Analysis of Mitigation Efficiency (η) to Cell Efficiency (CE), Correction Factor (δ), and Standard Weight of CO2 Emission (WCO2,emitted∘) Quantitatively Describing the Relationships of Energy and CO2 between Privileged ERCs and Appropriate Fossil Fuel Power Generations (A–E) For oxalic acid (A), carbon monoxide (B), formic acid (C), glyoxal (D), and acetic acid (E). (F) The ranges of CE required to reduce all the CO2 emitted for appropriate combinations of ERCs and fossil fuel power technologies. (G) Contour plot for δlimit over WCO2,emitted∘ and CE for the ERC to oxalic acid. (H) Compositions of δ in various situations. (I) For oxalic acid. Negligible δ in (A)–(F); non-negligible δ in (G)–(I). Joule 2018 2, 594-606DOI: (10.1016/j.joule.2018.02.003) Copyright © 2018 Elsevier Inc. Terms and Conditions