Descripción del proyecto
Hacia una escala redox universal y unificada pertinente para todos los disolventes
Las reacciones de oxidación-reducción, denominadas «reacciones redox», son la base de un sinfín de aplicaciones entre las que figuran la electrocatálisis y el almacenamiento electroquímico de energía. En estas reacciones, la transferencia de electrones entre dos especies da lugar a la oxidación (pérdida de uno o varios electrones) de una y la reducción (ganancia de uno o varios electrones) de la otra. El potencial electroquímico de los reactivos es una medida que se utiliza para predecir la viabilidad de una reacción redox. En la actualidad, se cuantifica a través de un disolvente específico en el que debe producirse la reacción. En el proyecto InnoChem, financiado con fondos europeos, se creará una escala redox unificada para comparar los potenciales electroquímicos en todos los medios.
Objetivo
The elementary steps underlying the reversible addition and removal of electrons from matter M –Metals, Molecules or Materials– are the fundament to describe redox chemistry, electrocatalysis and electrochemical energy storage. However, the electrochemical potentials of reaction partners are only comparable within one solvent. This is a consequence of the solvent specific standard states.
For this reason, it is a Grand Challenge to establish a Unified Redox Scale to compare electrochemical potentials in all media without extra-thermodynamic assumptions. To achieve this, we use an ‘ideal’ Ionic Liquid Salt Bridge setup to measure the Gibbs transfer energies between different solvents. The measured values, corrected for residual liquid junction potential contributions, will be used to directly connect potentials to the aqueous scale. This unifying solvent-independent scale will allow for knowledge-based comparison and selection of reagents for redox reactions in the next sections.
Reagents for deelectronation (removal of an e–) at high potential are scarcely available. Hence, we prepare perhalogenated radical cation salts that act as innocent Deelectronators (iD+) with high unified redox potentials. An iD+ converts a given neutral M to the ‘naked’ cation M+. iD+-salts are straightforwardly accessible and room-temperature stable materials. Conveniently, they are in part weighable in air. Combined with suitable non-reactive, weakly coordinating but polar innocent solvents and robust weakly coordinating anions, reactive cation salts are accessible.
Such reversible iD+-mediated redox-processes at high potential are appealing for electrosynthesis and -catalysis. To generate, study and apply these systems, we introduce a generally applicable innocent solvent family compatible with the high potential of iD+ and M+ – also with commercially available anions. Suitable iD+/solvent couples for targeted reactions are selected based on their position on the unified redox scale.
Ámbito científico
Programa(s)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Régimen de financiación
HORIZON-AG - HORIZON Action Grant Budget-BasedInstitución de acogida
79098 Freiburg
Alemania