Selective CO2 Reduction to CO and Alcohols without Platinum or Noble Group Electrodes

Descripción del proyecto

Conversión electroquímica mejorada del CO2: rentable, altamente selectiva y sostenible

Los compuestos que contienen carbono son la materia prima de una plétora de productos químicos y polímeros, entre los que se encuentran los plásticos, cauchos y detergentes. Como la mayoría proceden de recursos fósiles, las alternativas más ecológicas son un objetivo clave de la industria química. La conversión electroquímica del CO2 es una de las vías más prometedoras, pero afronta desafíos. Entre ellos se encuentran la necesidad de utilizar ánodos a base de iridio para evitar la acidificación de los electrolizadores de CO2 y la dificultad de conseguir una alta selectividad en la producción de alcoholes de alta densidad energética. El equipo del proyecto RECALLCO2, financiado por el CEI, intentará eliminar estos obstáculos. Desarrollará un novedoso diseño de célula electroquímica, arquitecturas catalíticas moleculares que superen las limitaciones actuales, y el acoplamiento con electrodos metálicos en lugar de carbono.

Objetivo

The electrochemical conversion of CO2 to carbon-based feedstocks represents one of few technological routes capable of replacing fossil fuel derivatives. Despite substantial advancements, however, major challenges impair CO2 electrolysis from matching its promise. Critically, steady acidification of CO2 electrolyzers during operation currently necessitates the use of iridium-based anodes. This is unacceptable from a cost and resource availability perspective. More fundamentally, while CO2 reduction to CO, formate and ethylene has become highly selective, the production of high-energy density alcohols with high selectivity has been elusive. To overcome these barriers, new scientific approaches are needed.

RECALLCO2 will resolve iridium dependencies and non-selective alcohol production in CO2 electrolysis through a combination of novel electrochemical cell design and the development of molecular catalytic architectures which break existing fundamental limitations. On the system design front, I will micro manipulate reagent, ionic and water fluxes to inhibit nickel corrosion pathways which presently necessitate iridium anodes. This will be the first-ever intrinsically stable CO2 electrolyzer capable of using nickel anodes.

A second pillar is the conceptualization that strong electronic-coupling of metal complexes to metal electrodes can eliminate redox-controlled reaction pathways on molecular catalysts. This counters decades of work using carbon electrodes as supports. Coupling with a metal electrode will delink electron transfers from a molecular catalysts oxidation states, and fundamentally change catalytic behaviour that currently restricts reactions to 2 electrons. Thus, CO2 reduction products such as methanol (6 electrons) and ethanol (12 electrons) will become viable. Utilizing this counterintuitive approach, I will push alcohol synthesis well beyond state-of-the-art selectivity and reaction rates, giving renewed promise for producing these compounds.