Density functional theory investigation of the role of Fe doped in boron carbide nanotube as an electro-catalyst for oxygen reduction reaction in fuel cells

A critical issue in enhancing the performance of polymer electrolyte membrane fuel cells (FCs) is the slow kinetics of the cathodic oxygen reduction reaction (ORR). The development of electrocatalysts with selectivity toward the four-electron (4e) pathway and high electrochemical activity to ORR reaction is important for fuel cell applications. Within the present study, it was found that boron carbide nanotube (BC3NT) is an encouraging ORR-EC based on density functional theory computations. In the pristine BC3NT, the neighboring B atoms with positive charges on the surface of the material surface were incapable of providing active sites for the dissociation of O. However, the ORR catalytic activity of BC3NT improved under the ligand effect due to the replacement of Fe atom, where there was a slight over-potential that was similar or lower than that of platinum (1 1 1), which demonstrated its superior ORR activity. The results suggest that BC-based materials are considered promising for ORR catalysis and for designing highly efficient ORR-ECs as alternatives to platinum-based catalysts.