Iron-embedded boron nitride nanosheet as a promising electrocatalyst for the oxygen reduction reaction (ORR): A density functional theory (DFT) study

We performed comprehensive density functional theory (DFT) calculations to explore the possibility of the Fe-embedded hexagonal boron nitride (h-BN) sheet as a novel electrocatalyst for ORR. Our results show that Fe atom can strongly bind with defective BN sheet and thus ensure its high stability. Moreover, O2 molecule is found to be strongly chemisorbed on Fe-embedded BN sheet with the adsorption energy of −1.76 eV, which can server as precursors for ORR, followed by its hydrogenation into OOH species rather than direct breakage of the O-O bond. Further, the HOOH species in the process of OOH reduction is shown to be unstable and dissociates into two OH group, suggesting that ORR catalyzed by Fe-embedded BN sheet is a direct four-electron pathway. Finally, on the basis of the calculations on the free energy change and activate energy of each step in ORR, we expect that Fe-embedded BN sheet exhibits good catalytic activity for ORR. Our results provide an useful guidance for the design and fabrication of novel and nonprecious BN sheet-based electrocatalyst for ORR as the alternative of expensive Pt catalysts.