The electrochemical oxidation mechanism of urea on a Ni(OH)2 catalyst in alkaline medium was investi-gated using in situ surface enhanced Raman spectroscopy. It was demonstrated that the urea oxidationfollows a catalyst regeneration mechanism. In the proposed mechanism, Ni(OH)2 is electrochemicallyoxidized to NiOOH that mediates the urea oxidation reaction. During the urea oxidation process, thecatalytically active NiOOH is chemically reduced to the inactive Ni(OH)2 by urea, concurrently, urea ischemically oxidized to its products. The inactive Ni(OH)2 is electrochemically oxidized to NiOOH dueto the prevailing high oxidation potential thus regenerating the catalyst for further oxidation of ureamolecules.
- Catalyst regeneration mechanism
- Hydrogen production
- In situ surface enhanced Ramanspectroscopy
- Nickel oxyhydroxide
- Urea electro-oxidation