Enhanced anodic catalytic performance in PrFeO3−δ of perovskite materials via Co-doping with Sr and VB subgroup metals (V, Nb, Ta)

Abstract

The anodic catalytic capability of PrFeO_3−δ is restricted by the Fe-site element type in the perovskite material structure due to its low electrical conductivity of electrons. Here, we present a strategy for tuning the Fe-site element type via Sr and VB subgroup metals (V, Nb, Ta) co-doping to enhance the anodic catalytic performance of PrFeO_3−δ anode materials. Our calculations show that Sr and Nb co-doping has suitable hydrogen adsorption energy for PrFeO_3−δ anode materials, and its adsorption energy is adjusted to −0.717 eV, which is more suitable to absorb the hydrogen molecule than other high-profile perovskite anode materials. Meanwhile, after the doped surface is adsorbed by hydrogen molecules, the bond length lengthens until it breaks, and one of the broken hydrogen atoms moves directly above the surface oxygen atom, which is beneficial for accelerating the anodic catalytic reaction. Thus, the Pr_0.5Sr_0.5Fe_0.875Nb_0.125O_3−δ material is a promising perovskite anode catalyst. Interestingly, the stability of PrFeO_3−δ is significantly affected by the oxygen vacancy content; the structural stability of the undoped system can be maintained via Sr and Nb co-doping to avoid decomposition, which provides new thinking to maintain the high stability of perovskite ferrite materials. Furthermore, we find that relative to the PrFeO_3−δ, the Pr_0.5Sr_0.5Fe_0.875Nb_0.125O_3−δ surface of hydrogen adsorption has obvious charge transfer and upward shift of the d-band center. Our anodic catalytic theoretical work shows that Sr and Nb co-doping can effectively enhance the catalytic performance of the PrFeO_3−δ ferrite materials.