Water splitting is an important process towards the generation of H2 as a renewable and sustainable energy source; however, the high overpotential and slow kinetics limit its applicability.
Most current photo- and electro-catalysts are expensive to make, not environmentally friendly and the processes consume a lot of energy. Some are not stable kinetically or require extreme conditions such as high pH.
Designing biomimetic, ligands that can stabilize water oxidation catalysts intermediates, which also include proton acceptor groups, within stabilizing catalytic systems (appropriate buffer conditions) enables the stabilization of the catalysts during the entire catalytic cycle lowering overpotential and increasing efficiency.
It was demonstrated that a peptoid ligand can be assembled in the presence Cu(II) ions to form a di-nuclear copper complex, and that the latter is a highly active electrocatalyst for water oxidation in borate buffer at mild pH and low over-potential. At these conditions faradaic efficiency was >90% at an overpotential of about 600 mV, and with about 45 kV/h required to produce 1 Kg, which is 10% lower than what is used in industry today.
- Cheap, environmentally benign and readily available materials
- Low applied potential
- Fast kinetics
Applications and Opportunities
Efficient hydrogen production by electrocatalysis