| AVS 63rd International Symposium & Exhibition | |
| Applied Surface Science | Tuesday Sessions |
| Session AS-TuP |
| Session: | Applied Surface Science Division Poster Session |
| Presenter: | Michael Dzara, Colorado School of Mines |
| Authors: | M.J. Dzara, Colorado School of Mines C. Ngo, Colorado School of Mines J. Christ, National Renewable Energy Laboratory P. Joghee, Colorado School of Mines C. Cadigan, Colorado School of Mines T. Batson, Colorado School of Mines R. Richards, Colorado School of Mines R. O'Hayre, Colorado School of Mines S. Pylypenko, Colorado School of Mines |
| Correspondent: | Click to Email |
Developing non-precious metal catalyst (NPMC) materials for the oxygen reduction reaction (ORR) is a critical research area in order to drive the widespread commercial adoption of low temperature fuel cells. Current technology uses Pt or other precious metal-based catalysts; by replacing these expensive precious metals with inexpensive, earth-abundant NPMCs, the economic feasibility of low temperature fuel cells can be significantly improved. However, improvements in the performance of NPMCs are needed in order to compete with precious metal-based catalysts. Perovskite oxide structures (ABO3)are one of the candidates among themany materials being evaluated as NPMCs for the ORR in alkaline media. Many elements can form perovskite oxide structures that are stable in alkaline media, and the properties of these structures can be tuned by doping the A and B sites, providing an extremely vast range of possible structures to explore.1 Performance of perovskite oxides has been shown to improve by creating a perovskite oxide/carbon composite, as carbon improves the conductivity of the composite and has an active role in catalyzing the ORR.2 However, like other NPMC chemistries perovskite oxides are heterogeneous by nature, and it is therefore difficult to correlate material properties with catalytic performance.
Here, our work focuses on understanding the interplay of surface chemistry and surface morphology of Ca0.9La0.1Al0.1Mn0.9O3-δ perovskite oxides and their composites with carbon. An aerogel synthesis method was used to produce Ca0.9La0.1Al0.1Mn0.9O3-δ perovskite oxides with surface areas from approximately 5-80 m2/g. By varying synthesis parameters, materials with different surface chemistry and morphology were produced. Detailed characterization of surface composition and morphology are performed using physisorption, x-ray photoelectron spectroscopy, and transmission electron microscopy equipped with energy dispersive X-ray spectroscopy. This information is correlated to rotating ring-disk electrode electrochemical measurements in alkaline media. These techniques help provide understanding of the surface properties of Ca0.9La0.1Al0.1Mn0.9O3-δ perovskite oxides and their impact on performance, providing a path towards optimization of the surface chemistry and morphology for improved catalytic performance.
References
1. Hardin, W. G., et al. (2014). Tuning the electrocatalytic…interactions. Chem. Mater., 26(11), 3368–3376.
2. Poux, T., et al. (2012). Dual role…reaction. Catalysis Today, 189(1), 83–92.