Executive Summary : | The depletion of conventional fossil fuels has led to the search for sustainable, clean, and renewable energy sources, particularly hydrogen gas produced through water splitting under photolytic or electrolytic conditions. This is an eco-friendly renewable energy source due to its high gravimetric calorific value and zero emissions during combustion. However, the high kinetic energy barriers associated with half-cell reactions (HER and OER) make water splitting slow and inefficient. To achieve maximum efficiency, efficient catalysts operating at very low overpotential are desirable. Cobalt-based complexes have emerged as hydrogen evolution catalysts in aqueous and non-aqueous solutions, with polypyridyl-based complexes being most effective in evolving hydrogen from a fully aqueous solution due to their greater solubility and stability. However, highly efficient and robust cobalt-based molecular HER catalysts generating hydrogen from aqueous solution at very low overpotential and high turnover number are yet to be developed. The researchers plan to develop cobalt complexes supported by newly designed tetradentate and pentadentate polypyridyl ligand platforms to contribute to the hydrogen fuel economy. They also plan to synthesize unsymmetrical tetradentate ligands with a combination of imine and carboxamide arms, allowing cobalt complexes to display low overpotential, high turnover frequency, and stability during water reduction activity. |