Nonreducing Ambient Atmosphere: Pulsed Electric Current Treatment of Co/Ni Doped Perovskite Oxides to Achieve Exsolution Enhanced Electrochemical Performance

Abstract

Exsolution of metal nanoparticles (NPs) on the surface of perovskite oxides is a promising approach for developing advanced catalytic materials through a “bottom-up” design strategy. Under a nonreducing ambient atmosphere utilizing pulsed electric current (PEC) treatment to promote the exsolution of perovskite oxides effectively overcomes the limitations inherent in conventional high-temperature vapor phase reduction (HTVPR) in situ exsolution methods. This paper presents the successful synthesis of (La0.7Sr0.3)0.8Ti0.93Ni0.07O3 (LSTN) perovskite oxide and (La0.7Sr0.3)0.8Ti0.93Co0.07O3 (LSTC) perovskite oxide using the sol–gel method, followed by PEC treatment at 600 V, 3 Hz, and 90 s. Utilizing various characterization techniques to confirm that PEC treatment can promote the exsolution of Co and Ni NPs under a nonreducing ambient atmosphere, the results indicated that the exsolved perovskite oxides exhibited significantly improved electrochemical properties. Furthermore, compared to the LSTN-PEC, LSTC-PEC demonstrates a lower onset potential of 1.504 V, a Tafel slope of 87.16 mV dec–1, lower impedance, higher capacitance, superior catalytic activity, and long-term stability.