A novel method for rapidly functionalizing perovskite oxides

Abstract

High-performance perovskite oxides are instrumental in catalytic processes and energy conversion. The exsolution of metallic nanoparticles from perovskite oxide hosts to form metal/oxide heterogeneous catalysts provides unprecedented opportunities for manipulating the catalytic activity of perovskites. Herein, we design and demonstrate a new approach to rapidly trigger exsolution and tune the electrochemical performance of perovskites. We show that by applying pulsed thermal shock several times (∼50 ms pulse width) and voltage shock for ∼40 s, exsolution-based products can be prepared on a timescale of seconds. With an increase in the number of pulses, the particle density increases first due to an increase in the concentration of oxygen vacancies that can serve as nucleation sites and then reaches a threshold governed primarily by the content of exsolvable metal atoms in the host lattice. Owing to the additionally generated active sites and conducting paths for active species, perovskite activity is significantly improved, thus eventually yielding a prominent enhancement in electrochemical performance.