Fuel Cells Technology and Electrode Materials for a Sustainable Future - Chapter 9: Emerging Materials for Hydrogen Oxidation Reaction

There is a compelling need for cost-effective, highly efficient, and long-lasting electrocatalysts to address the global energy challenges associated with the oxygen reduction reaction (ORR). In recent years, there has been a significant increase in research focused on electrocatalysts for the ORR that are based on minerals that are not classified as noble metals. In this chapter, we begin by presenting a set of evaluation criteria for ORR. Subsequently, we proceed to examine the current electrocatalysts employed for ORR, classifying them into several categories including metals/alloys, oxides/hydroxides, chalcogenides/oxides, phosphides/oxides, phosphates/borates, and other compounds. Furthermore, we analyze the advantages and disadvantages associated with each category. To enhance the efficacy of ORR electrocatalysts, it is imperative to provide a comprehensive overview of the existing knowledge pertaining to the reaction mechanisms and practical implementations of ORR. In this analysis, we explore the present state, challenges, and potential outlook of ORR electrocatalysts that do not depend on precious metals.