A-site vacancy induced electronic engineering of perovskite for synergistic modulation of redox activity and magnetocaloric effect

Abstract

Realizing “Power to Syngas” by electrifying chemical reactors via induction heating is one of the key enabling technologies to decarbonize the chemical industry. Nevertheless, developing catalysts for the induction heating process that can simultaneously serve as magnetic susceptors under high-temperature conditions remains challenging. Herein, we formulate a A-site vacancy induced electronic engineering strategy and, accordingly, synthesize a series of LaFe0.5Al0.5O3 perovskite catalysts with different amounts of La vacancies (VLa) (LFAO, 1.5 M-LFAO, and 3 M-LFAO). In this way, we tune both the redox activity and the magnetocaloric effect (MCE) of perovskite and, for the first time, achieve induction heating methane partial oxidation coupled with CO2 splitting for syngas production. Compared with the reported catalysts, the 3 M-LFAO had not only superior syngas and CO yields (101.84 L·kg cat−1/54.96 L kg cat−1) but also a great MCE (875 °C). Spectroscopic investigations and DFT calculations rationalize these observations and demonstrate that the VLa cause a unique Fe4+–O2-–Fe3+ configuration in perovskite, accounting for an upshift of Fe 3d and O 2p band centers and therefore enhancing redox activity and MCE. This work deepens the understanding of the relationship between catalysis and MCE and unlocks the novel guidance to design induction heating chemical processes.