Groupe Kornienko
Translation of molecular catalysts into highly functional interfaces for CO2 and N2 reduction
Abstract:
Greenhouse gas emissions, such as CO2 emissions, are a global issue requiring a solution to reduce the effects of global warming and climate change on the environment. A proposed solution is through the electrochemical reduction of CO2 coupled with other technologies within carbon capture, utilisation, and storage (CCUS) and renewable energy sources. Furthermore, nitrogen reduction reaction (N2RR) has received more attention due to the potential of generating a greener source of NH3 lowering this essential chemical’s carbon footprint. Because of this, many catalysts are being developed which can be split into two types: solid materials and molecular catalysts. Here we investigate the use of molecular catalysts, such as transition metal polypyridine complexes with the potential for high efficiencies and product selectivity.
The modularity of molecular catalysts enables the tuning of both active site and peripheral units to maximize functionality, thus rendering them as ideal model systems to explore fundamental concepts in catalysis. Hydrophobicity is often regarded as an undesirable aspect that hinders their dissolution in aqueous electrolytes. In contrast, we modified established Co terpyridine catalysts with hydrophobic perfluorinated alkyl side chains and took advantage of their hydrophobic character by utilizing them not as dissolved species in an aqueous electrolyte but at the gas-liquid-solid interfaces on a gas diffusion electrode (GDE) applied towards the electrochemical reduction of CO2. Additionally, molecular catalysts have the potential to be used for nitrogen fixation and hydride transfer. Specifically, we demonstrate this through the use of a mono-terpyridine Ni complex coupled with a palladium membrane reactor, which allows for an organic media with higher nitrogen solubility to be used. Our initial results show the potential for reduction of N2 to ammonia within this system.
