Abstract

Direct ethanol fuel cells (DEFCs) have been identified as a promising technology in renewable energy applications as it uses a sustainable, carbon-neutral liquid fuel (ethanol) to generate electrical energy and is well-suited for portable and mobile applications. But before this technology can become viable for implementation in wide range of devices, specific issues related to efficiency, durability, and scalability must be addressed. This chapter discusses the fundamental concepts of DEFC, the role of oxygen reduction reaction (ORR), and recent development in ORR catalyst design for application in DEFC. It focuses on the challenges associated with the cathodic reaction and provides an overview of the strategies employed to engineer the catalytic material at the cathode for boosting the ORR performance by improving selectivity, kinetics, and overpotential requirement.