Low-Temperature Electrocatalysis

Low temperature electrocatalysis is central to many energy conversion and storage technologies. For example, the energy efficiencies of proton exchange membrane fuel cells (PEMFCs), anion exchange membrane fuel cells (AMFCs), and Li-air batteries. These electrochemical devices directly convert fuels to electricity carried by proton, hydroxide ion or lithium ion at room temperature and rely heavily on oxygen reduction reaction (ORR) and the reverse reaction, oxygen evolution reaction (OER) electrocatalysts. The energy conversion of these low temperature electrochemical devises is typically less than 70% due to the slow kinetics of the ORR and OER. The loss of efficiency due to the sluggish electro-kinetics is even further pronounced for direct methanol and other alcohol fuel cells, which also suffers from slow methanol oxidation kinetics in tthe anode in addition to the already sluggish ORR kinetics in the cathode.

Discovery of cost-effective, stable, highly efficient electrocatalytic surfaces that can catalyze the ORR, the OER, and small organic molecule (e.g. methanol) oxidation can improve the conversion efficiency and is an enabling step for the commercialization of PEMFCs, AMFCs, electrolyzers, and metal-air batteries. A lack of fundamental understanding of the reaction mechanisms and catalyst design principles has been the major hurdle toward better low temperature electrocatalysts.

In addition, novel synthesis methods and characterizations to produce and confirm the formation of the highly efficient structure are needed to create new types of catalyst that are precious metal free. These challenges also apply to the cases of small organic molecule oxidation reaction, where discoveries of new catalysts that can function better and made of cheaper materials are seen as enabling steps toward commercialization of these electrochemical energy technologies.