(433d) High-Temperature CO2 Electroreduction into Carbon Nanostructures in Molten Salt Electrolyte for Carbon-Negative MSCO2RR

The electrochemical CO₂ reduction reaction (CO₂RR) represents a critical approach toward the carbon-neutral or carbon-negative production of value-added products. In this presentation, we will present design rules to control the electrochemical parameters and microenvironment towards CO₂ conversion to carbon nanotubes and other nanostructured carbons with high Faradaic efficiency (>80%) in molten salt electrolyte. These carbon nanostructures are particularly attractive to produce fixed forms of carbon for carbon-negative processes that do not lead to the re-emission of CO₂.

To this end, we will describe our efforts in molten salt CO₂ reduction reaction (MSCO₂RR) to valuable carbon nanostructures. Overall, carbon nanostructures also represent useful value-added products with market value for CNTs on the order of $100 USD/kg. In contrast to aqueous CO₂ electroreduction, molten salt electrochemistry offers a microenvironment that can convert CO2 to cathodic solid carbon via an electrochemical CO₂ reduction reaction. Through systematic experiments, we elucidate the effects of changing electrolyte, catalyst composition, and temperature, amongst other factors, to control carbon nanostructure growth, as will be described in this presentation. Finally, informed by the design principles that we have discovered, we will share our findings on the technoeconomic analysis of MSCO₂RR, which suggest that MSCO₂RR to CNTs can be a profitable CO₂-negative technology at a commercial scale, suggesting a viable route to commercialization of this CO₂-negative technology.