CO2 reduction using artificial metalloenzymes hybrids for formic acid synthesis

• Grant number: 19/25762-7
• Support Opportunities: Scholarships abroad - Research
• Effective date (Start): July 01, 2021
• Effective date (End): June 30, 2022
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Caterina Gruenwaldt Cunha Marques Netto
• Grantee: Caterina Gruenwaldt Cunha Marques Netto
• Host Investigator: Brian Dyer
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Research place: Emory University, United States

Abstract

Carbon dioxide is a C1 source molecule of great interest due to its recyclability in nature. Its reduction can yield CO, formate, formaldehyde, methanol or methane, rendering low product selectivity when enzymes are not employed in the system. However, enzymes add a high aggregated value to the catalyst and most of them are cofactor dependent, hampering their employment due to the lack of cheap and efficient recycling systems for these cofactors. The enzyme formate dehydrogenase from Candida boidinii (CbFDH) is an enzyme able to selectively reduce CO2 to formate, an important chemical species in the sustainable production of H2. However, CbFDH possess a low thermal stability and low yields in non physiological conditions. To overcome these issues, enzyme immobilization can be used to increase the CbFDH thermal stability and the association to carbonic anhydrase (CA) can be employed to increase the reaction yield, but a bienzymatic system can increase the catalyst cost and destabilize the system. Therefore, this project aims at the association of a CA mimic on CbFDH to hydrate/dehydrate CO2 near the CbFDH active site, as a delivering system to the redox reaction. This hybrid will generate a CbFDH containing a metal, which will be immobilized on quantum dots to increase the thermal stability of the enzyme and to regenerate the electrons used in the reaction by photoreduction of methylviologen, a molecule able to act as a NADH substitute. In essence, it is expected to obtain an artificial metalloenzyme system immobilized on quantum dots for the sustainable reduction of CO2.