Tailored DC/Sputtered Niobium Oxide Properties for PEM Electrolysis Application

The fast renewable energy source penetration is creating often mismatch in grid power demand, and is making the case for new energy storage solutions. Hydrogen-based energy conversion technology is considered the most tenable large and long-term scale alternative, and proton exchange membrane (PEM) water electrolysis is seen as one of the most efficient and simple ways to obtain high purity hydrogen [1]. An important drawback in these systems is represented by the oxygen evolution reaction (OER) that is strongly influenced by the catalysts stability against oxidation potential [2].

The aim of this work was to tailor the niobium oxide properties using DC-magnetron sputtering deposition, and to correlate its structure with their electrocatalytic activity toward the Oxygen Evolution Reaction for PEM Electrolyser applications. The influence of the working parameters (deposition pressure, sputtering power and thickness) towards catalysts structure is studied by Uv-Vis and FTIR spectroscopy, X-ray diffraction (XRD), SEM, Rutherford Back Scattering experiments, and four-points resistivity measurements. AC impedance measurements, and cycling voltammetry for electrochemical surface area (ECSA) determination is carried out. The Niobium oxides are deposited on various substrates from transparent (optical glass) for optical and electrical measurements, to highly conductive glassy carbon for compositional and electrochemical investigations.

[1] C. Rozain Caroline, P. Millet, Electrochimica Acta, 131 (2014) 160-167.

[2] V. K. Puthiyapura,, S. Pasupathi, S. Basu, X. W, H. Su, N. Varagunapandiyan, B. Pollet, K. Scott, Int. J. of. Hydrogen Energy, 38 (2013) 8605-8615.