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

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 (La 0.7 Sr 0.3 ) 0.8 Ti 0.93 Ni 0.07 O 3 (LSTN) perovskite oxide and (La 0.7 Sr 0.3 ) 0.8 Ti 0.93 Co 0.07 O 3 (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.