Gold-Supported Cerium-Doped NiOx Catalysts for Water Oxidation

The development of high-performance catalysts for the oxygen evolution reaction (OER) is critical for converting renewable electricity to fuels and chemicals cost-efficiently.[1] Herein we report the significant enhancement in the OER activity of electrodeposited NiO_x films resulting from the dual effects of using a gold metal support and a cerium dopant.[2] This NiCeO_x-Au catalyst achieves high OER activity in an alkaline environment, and is among the most active OER electrocatalysts reported to date. Based on theoretical modelling coupled with experimental observations, we attribute the activity to a combination of geometric, electronic and support effects, where highly active under-coordinated sites at the oxide-support interface are modified by the local chemical binding environment and by doping the host Ni oxide with Ce. The NiCeO_x-Au catalyst is further demonstrated in a device context by coupling it with a nickel-molybdenum hydrogen evolution catalyst in a water electrolyser setup, which delivers 50 mA consistently at 1.5 V over 24 hours of continuous operation. This work deepens the understanding of complex multi-component catalytic systems by showing how electronic, geometric and support effects can be combined to enhance catalytic activity.

References

[1] Yang, Z., Zhang, J., Kintner-Meyer, M.C.W., Lu, X., Choi, D., Lemmon, J.P. & Liu, J. Electrochemical energy storage for green grid. Chem. Rev. 111, 3577-3613 (2011).

[2] Ng, J.W.D., Garcia-Melchor, M., Bajdich, M., Charthranont, P., Kirk, C., Vojvodic, A., Jaramillo, T.F. Gold-Supported cerium-doped NiO_x catalysts for water oxidation. Nat. Energy. 1, 16053 (2016).