Air electrode development is one of the most challenging steps in the design of lightweight and efficient metal-air batteries and fuel cells. The best performing oxygen catalysts often contain precious metals at a high manufacturing cost. In this paper, two low-cost catalysts for the oxygen reduction (ORR) and evolution reactions (OER), based on LSFCO perovskite and Ni-Fe hexacyanoferrate, were compared with a precious metal palladium catalyst on carbon (Pd/C). LSFCO/C showed the best all-round performance as a single bifunctional catalyst but Pd/C had the strongest ORR activity. Ni-Fe hexacyanoferrate is straightforward to manufacture in industrial quantities, and is more active for the OER than palladium and LSFCO perovskite at small loadings < 5 mg cm-2. By mixing a small loading of Pd/C with Ni-Fe hexacyanoferrate, lower overpotentials for both the ORR and OER can be reached, with the difference in potential between the two reactions being only 0.62 V at a current density of 20 mA cm-2. The effect of catalyst loading of each catalyst on the gas-diffusion electrode was studied, and rotating disk voltammetry was used to study the catalytic behavior of the Ni-Fe hexacyanoferrate catalyst.
A comparison of Pd/C, perovskite, and Ni-Fe hexacyanoferrate bifunctional oxygen catalysts, at different loadings and catalyst layer thicknesses on an oxygen gas diffusion electrode
Baglio V;
2018
Abstract
Air electrode development is one of the most challenging steps in the design of lightweight and efficient metal-air batteries and fuel cells. The best performing oxygen catalysts often contain precious metals at a high manufacturing cost. In this paper, two low-cost catalysts for the oxygen reduction (ORR) and evolution reactions (OER), based on LSFCO perovskite and Ni-Fe hexacyanoferrate, were compared with a precious metal palladium catalyst on carbon (Pd/C). LSFCO/C showed the best all-round performance as a single bifunctional catalyst but Pd/C had the strongest ORR activity. Ni-Fe hexacyanoferrate is straightforward to manufacture in industrial quantities, and is more active for the OER than palladium and LSFCO perovskite at small loadings < 5 mg cm-2. By mixing a small loading of Pd/C with Ni-Fe hexacyanoferrate, lower overpotentials for both the ORR and OER can be reached, with the difference in potential between the two reactions being only 0.62 V at a current density of 20 mA cm-2. The effect of catalyst loading of each catalyst on the gas-diffusion electrode was studied, and rotating disk voltammetry was used to study the catalytic behavior of the Ni-Fe hexacyanoferrate catalyst.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
