TU Berlin team develops multifunctional catalyst for ORR and OER for fuel cells or rechargeable metal-air batteries
One of the challenges in electrocatalysis (be it for solar fuels, fuel cells or rechargeable metal-air batteries) is to find an effective catalyst that will reduce (oxygen reduction reaction, ORR), as well as generate (oxygen evolution reaction, OER), oxygen at moderate temperatures. A team from Technische Universität Berlin now reports developing cobalt-manganese-based (CoMn2O4 and MnCo2O4) spinel microspheres as highly efficient multifunctional catalysts that unify the electrochemical OER with oxidant-driven and photocatalytic water oxidation as well as the ORR.
A paper on their work is published is the journal ChemSusChem.
The as-prepared spinels display excellent performances in electrochemical OER for the cubic MnCo2O4 phase in comparison to the tetragonal CoMn2O4 material in an alkaline medium. Moreover, the oxidant-driven and photocatalytic water oxidations were performed and they exhibited a similar trend in activity to that of the electrochemical OER.
Remarkably, the situation is reversed in ORR catalysis, that is, the oxygen reduction activity and stability of the tetragonal CoMn2O4 catalyst outperformed that of cubic MnCo2O4 and rivals that of benchmark Pt catalysts. The superior catalytic performance and the remarkable stability of the unifying materials are attributed to their unique porous and robust microspherical morphology and the intrinsic structural features of the spinels. Moreover, the facile access to these high-performance materials enables a reliable and cost-effective production on a large scale for industrial applications.—Menezes et al.
Menezes, P. W., Indra, A., Sahraie, N. R., Bergmann, A., Strasser, P. and Driess, M. (2014) “Cobalt–Manganese-Based Spinels as Multifunctional Materials that Unify Catalytic Water Oxidation and Oxygen Reduction Reactions,” ChemSusChem doi: 10.1002/cssc.201402699