Chapter 4 - The Electrochemical Conversion of Carbon Dioxide to Carbon Monoxide Over Nanomaterial Based Cathodic Systems: Measures to Take to Apply This Laboratory Process Industrially

Abstract

Among stoichiometric, biochemical, thermochemical, photochemical, photoelectrochemical, and electrochemical methods developed so far to convert waste-stream greenhouse carbon dioxide (CO2) gas into value added chemicals, the most current consensus is that only the electrochemical routes can deal with the problems of (1) CO2 associated global warming, (2) storing renewable energy in high-energy density liquid fuels, and (3) depletion of fossil fuels. By making certain improvements in electrolyzer design and experimental parameters to the reported electrochemical reduction of CO2 (ERC) to CO processes, which utilize room temperature ionic liquids (RTILs) as helper catalysts, similar to the H2 produced in commercial alkaline electrolyzers, the CO can also be produced with desired current densities (>100 mA/cm2), faradaic efficiencies, and over-potentials for practice in industry. The electrochemical direct splitting of CO2 to CO process (CO2 → CO + ½O2) is more beneficial than the one (CO2 + 2H+ + 2e− → CO + H2O) involving protons (H+) in the reduction process. ERC to CO production offsets the cost incurred in process while offering all the benefits obtained from implementing the CO2 sequestration process. Because each day several countries generate several million tons of CO2 gas, implementing this ERC to CO process commercially would have a major impact on the energy economy. The improvements to be made to turn these reported lab-scale ERC processes involving nanomaterial-based active cathodic systems into industrial processes are systematically presented and explored in this chapter, citing all important and relevant references.