Perovskites + Carbon as Oxygen Catalysts at Low Temperature

Electrochemical conversion processes such as oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are critical to sustainable energy technologies including alkaline fuel cells, direct-solar or electricity-driven water splitting, and rechargeable metal-air batteries. However, the high cost and scarcity of the state-of-the art oxygen catalysts based on precious metals prohibits the commercialization of those clean energy technologies. One family of promising non-precious oxygen catalysts in alkaline media are transition metal oxides and ABO3 perovskites because of their potentially high catalytic activity and compositional flexibility. We have developed a number of composites and hybrids including of carbon and MnO[1], Ba0.95La0.05FeO3-δ (BLF) [2], and Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) [3]. For example, introducing nitrogen-doped mesoporous carbon (NC) as the catalyst support, the BSCF/NC hybrid exhibits significant activity towards ORR and OER [3]. The interaction between perovskite and carbon is key to improve the activity. We have investigated the role of carbon, providing a useful reference for further optimization of the catalytic activity of perovskites.

References:

[1] Y. Gao, H. Zhao, D. Chen, C. Chen, and F. Ciucci. In Situ Synthesis of Mesoporous Manganese Oxides/Sulfur-doped Graphitized Carbon as a Bifunctional Catalyst for Oxygen Evolution/Reduction Reactions. Carbon, 94, 1028–1036 (2015) link[2] H. Zhao, C. Chen, D. Chen, M. Saccoccio, J. Wang, Y. Gao, T.H. Wan, F. Ciucci. Ba0.95La0.05FeO3−δ Multi-Layer Graphene as a Low-Cost and Synergistic Catalyst for Oxygen Evolution Reaction Carbon, 90, 122-129 (2015) link[3] J. Wang et al. Submitted