Executive Summary : | The increase in global temperature is primarily due to an increase in CO₂ concentration in the atmosphere, leading to a growing interest in CO₂ capture and utilization. CO₂ reduction to energy-enriched chemicals like carbon monoxide (CO), formic acid (HCOOH), formaldehyde (HCHO), methanol (CH₃OH), and methane (CH₄) using solar or electrical energy is a key research topic. The two-electron reduction of CO₂ followed by reactions with protons has been extensively studied, but research on photocatalytic and electrocatalytic multi-electron reduction of CO₂ with more than two electrons has been limited. Most research on CO₂ conversion to methanol has focused on thermal hydrogenation, which requires high operating temperatures and externally generated H₂. It is desirable to achieve multi-electron CO₂ reduction at ambient temperature using renewable sources like electricity or light energy. A specific type of ruthenium-based polypyridyl complexes with a similar structure to the redox coenzyme nicotinamide adenine dinucleotide (NAD+)/NADH (hydride-reduced form) has shown promise for solar/electrical energy conversion processes. However, multi-electron reduction of CO₂ has not been achieved with these complexes due to their low hydricity. This proposal aims to modify the NAD ligand to deliver transition metal NADH complexes with increased hydricity, aiming for multi-electron CO₂ reduction electrochemically. Additionally, the proposal aims to achieve electro-reduction of carbonyl compounds, as most electrochemical systems reported metal-hydride (M-H) as an effective intermediate for such reduction at high reduction potentials. |