Non-precious metal electrocatalysts design for oxygen reduction reaction in polymer electrolyte membrane fuel cells: Recent advances, challenges and future perspectives

• Development in oxygen reduction reaction (ORR) electrocatalysts for fuel cells. • Non-precious metals electrocatalysts with high-electrocatalytic performance. • Carbon-based nanostructures with high surface area and increased active sites for ORR. • Metal-organic framework (MOF) derived electrocatalyst for ORR. • Single atom-based catalysts (SACs) are studied as efficient ORR electrocatalyst. The problem of renewable energy is appealing owing to cumulative power demand, the randomness of the increasing oil costs, and environmental issues. Amongst the numerous renewable energy sources, the fuel cell is acquiring more attractiveness owing to their higher efficiency, cleanliness, and cost-effective supply of power required by the clients. The key issue in the extensive commercial applications of polymer electrolyte membrane fuel cell is the usage of platinum based catalyst that is essentially required for the feasible oxygen reduction reaction. The enhancement of ORR performance, stability, and low cost are the main concerns of the non-precious metals catalyst. This review is focused on the development in non-precious nanomaterial-based electrocatalysts and emphasis to the several kinds of non-noble electrocatalysts with enhanced ORR efficiency. Future prospective and directions are suggested in this review for the further improvement in the strategy to the design and development of highly efficient and low-cost electrocatalyst for polymer electrolyte membrane fuel cells.