Application of carbon-based electrocatalysts derived from waste materials in fuel cells and electrolyzers

Abstract

The world's population is estimated to reach 9.7 billion by 2050, speculating towards compelling global population growth. Consequently, a rapid increase in energy demand would arise, indicating the need for the development of energy sources. For predicting the future energy demands and resource allocation, understanding population growth plays a crucial role. A lack of availability of natural resources has been reported owing to an increase in demand and cost. Fossil fuels are finite natural energy resources that are depleting rapidly. In order to revamp energy production, a potential alternative to traditional fossil fuels is the fuel cell technology. With the rapid increase in energy demands, fuel cells play crucial roles in providing enduring energy solutions. In fuel cells, electro-catalysts are vital components expediting the conversion of chemical energy into electrical energy. For ameliorating the performance of fuel cells, the development of efficient electrocatalysts is essential. Currently, Pt-based materials are scrutinized because they have the characteristics of achieving high wave potential, high onset potential and high limiting current density. However, the main impediments to making them industrially viable include their resource scarcity, poor durability and high cost. Thus, currently, the main aim of researchers is to substitute Pt-based materials with efficient, cost-effective and stable metal-based or metal-free materials. For this purpose, their centre of attention is carbon-based electro-catalysts. For electrochemical energy conversions and storage applications, C-based electro-catalysts are recognized as promising alternatives to traditional electro-catalysts owing to their excellent properties of high surface area, electrical conductivity and stability and enhanced catalytic activity. This review audits the contemporary advancements in C-based electro-catalysts derived from waste materials, emphasizing their applications in fuel cells and electrolyzers and discussing the future perspectives of these waste-derived electro-catalysts.