Macrocyclic cyanocobalamin (vitamin B 12 ) as a homogeneous electrocatalyst for water oxidation under neutral conditions.

Highly water-soluble cyanocobalamin (also known as vitamin B-12) is the most structurally macrocyclic complex comprising cobalt in the center of a corrin ring. Interestingly, it acts as a robust electrocatalyst in water oxidation at similar to 0.58 V overpotential with a faradaic efficiency of 97.50% under neutral buffered conditions. The catalyst is impressively stable even after long-term bulk electrolysis, and homogeneous in nature, as established by a series of experiments and characterization techniques.