Environmental pollution is a major concern due to the extensive use of fossil fuels to meet the current energy requirements. There is an imminent need for clean and sustainable energy technologies. Among the various energy conversion technologies, fuel cells offer a combination of cost-effectiveness, clean operation, and high energy density. However, the kinetically sluggish oxygen reduction reaction (ORR) makes this energy conversion system expensive. This is since the sluggishness is compensated with high platinum loading. Also, catalyst stability and durability are a matter of concern for Pt/C.
For catalysis, metal oxides continue to be interesting from the standpoint of activity and stability. In this work, we have divided our objectives into two parts. In the first part, we aim to improve the ORR performance of metal oxide-based catalysts using a nano-compositing approach without using any precious metal. The next part aims to find robust catalyst support based on metal oxides or metal oxides/carbon to reduce dependence on precious metals such as Pt for oxygen reduction reaction in a fuel cell.
In this work, we have chosen different types of reducible oxides such as TiO2, ZnO, CeO2, WO3 for our studies. The advantage of reducible oxides is that they form oxygen vacancies readily. In fact, these vacancies, when present on the surface, enhance the ORR activity. Most importantly, all the oxides chosen (TiO2, ZnO, CeO2, WO3) have earth-abundant constituents and hence are low cost and offer excellent stability in both acidic and alkaline mediums. In this talk, I will discuss a few preliminary results obtained in our study for ORR through the nano-compositing approach. I will also present the proposed roadmap.