Is electrochemical CO₂ reduction the future technology for power-to-chemicals? An environmental comparison with H₂-based pathways

Abstract

Minimum development requirements for electrochemical CO2 reduction (eCO2R) to compete against H2-based power-to-chemical pathways.

Combining First-Principles Kinetics and Experimental Data to Establish Guidelines for Product Selectivity in Electrochemical CO2 Reduction

“…Globally increasing temperatures and climatic anomalies demand means for reducing greenhouse gases in the atmosphere . Electrochemical CO 2 reduction (eCO 2 R) is considered as a promising route to close the anthropogenic carbon cycle by converting the major waste gas, CO 2 , into high-value fuels and chemicals using renewable electricity. , Substantial advancements in the design of CO 2 electrolyzers have been made recently, − approaching industrially relevant current densities. , However, with the exception of the 2e – products, carbon monoxide − and formate, , the energy efficiency of eCO 2 R is still poor, owing to the substantial overpotential needed to produce further reduced chemicals. , Furthermore, the large palette of simultaneously produced chemicals beyond 2e – products within eCO 2 R and the ubiquitous competition with the hydrogen evolution reaction (HER) hinders commercialization and creates the need to couple electrolyzers to costly separation techniques. − Thus, it is essential to improve both the intrinsic activity and selectivity toward the desired high-value products, such as ethylene and ethanol, in order to make eCO 2 R an economically viable process for CO 2 valorization.…”

Paired Electrosynthesis of Formic Acid from CO2 and Formaldehyde from Methanol

“…Electrochemical CO 2 reduction (CO2R) is a promising technology to produce base chemicals and replace fossil feedstocks. − A major challenge of CO2R is the high electrical energy demand and the resulting energy costs. , Typically, cathodic CO2R is paired with anodic oxygen evolution reaction (OER), with OER accounting for the majority of the cells’ energy demand . Recent literature has focused on replacing energy-intensive OER with organic oxidation reactions, which can reduce the energy demand and produce additional value-added products. − In this way, organic oxidation reactions can reduce the carbon footprint and improve economic viability of CO2R processes. , …”

Catalysis for an electrified chemical production

“…In a medium-term scenario (year range 2030-2040), we may expect to see the introduction of directly electrified chemical processes on the market, e.g., processes where RES provides the energy necessary for the reaction directly, in the form of either activated reactants (as in plasma-catalysed processes) [59] or of charged species generated on the surface of the catalyst by application of potential, e,g, electrocatalysis [12,[60][61][62][63] or by light absorption in a semiconductor, e.g. photocatalysis [64][65][66].…”