Co-Electrodeposition of Nanostructured Ce-NiOx on Stainless-Steel Substrates for the Oxygen Evolution Reaction under Alkaline Conditions

The development of cost-effective catalysts that can be fabricated at scale for electrochemical water oxidation is an ongoing challenge. Here it is shown that stainless-steel AISI316 is an appropriate support electrode for a co-electrodeposited Ni-CeOx catalyst for the oxygen evolution reaction (OER) under alkaline conditions. Optimal OER performance is achieved via a cyclic voltammetric deposition protocol rather than constant potential deposition for the catalyst layer. An overpotential of 300 mV at a current density of 10 mA cm(-2) is recorded with a Tafel slope of 43 mV dec(-1) while the catalyst also demonstrates long-term stability. It is also found that the catalyst layer changes significantly after the OER. This includes changes to the catalyst morphology, distribution of oxidation state, and speciation as well as the transformation from an entirely amorphous material into one containing crystalline regions. This simple one-step electrodeposition process on a cost-effective substrate should, in principle, facilitate the fabrication of low-cost electrolyzers.