Molecular Catalysts - for Urea Electrooxidation

In order to meet the growing global demands for energy in the age of environmental awareness, alternative clean energy sources must be explored. Hydrogen gas is such a source of energy, with water being the only byproduct in its energy conversion process. Urea electrolysis is a promising new technology that has the capacity to produce high-purity hydrogen from sustainable sources, such as wastewater (shown in scheme below). Urea is a highly attractive hydrogen carrier, because it is abundant, stable, non-toxic and non-flammable, and can be stored and transported conveniently, since it is solid under ambient conditions. Schematic representation of Urea Management Different solid-state electrocatalysts, particularly nickel- based materials, have been studied extensively for urea conversion, providing relatively high current densities and low over potentials for its oxidation to CO2 and N2. However, solid state catalysts are difficult to control, manipulate and study at the atomic level. In order to improve urea conversion, we aim to develop molecular catalysts that can be fine-tuned relatively easily at the atomic level and studied in great detail using methods that are common for such molecular systems, such as NMR spectroscopy and single-crystal X-ray crystallography. To the best of our knowledge, no molecular system has thus far been reported to promote the electrochemical conversion of urea. Herein, we describe our efforts to investigate molecular catalysts of different transition metal complexes (e.g.; Co, Ni, Mn, Cu) as molecular catalyst for urea conversion, using various ligands set ranging from such as phenol-imines to macrocyclic amine complexes.