CO2 Reactivity on Cobalt-Based Perovskites

Understanding the interaction of CO2 with perovskite metal oxide surfaces is crucial for the design of various perovskite (electro)chemical functionalities, such as solid oxide fuel cells, catalytic oxidation reactions, and gas sensing. In this study, we experimentally investigated the reactivity of CO2 with a series of cobalt-based perovskites (i.e., LaCoO3, La0.4Sr0.6CoO3, SrCoO2.5, and Pr0.5Ba0.5CoO3−δ) by a combined ambient-pressure XPS (AP-XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) approach. Isobaric measurements by AP-XPS on epitaxial pulsed laser deposition-grown (100)-oriented thin films under 1 mTorr CO2 showed the formation and uptake of adsorbed adventitious-like C–C/C–H, −CO species, monodentate carbonate, and bidentate (bi)carbonates. DRIFTS measurements on powder samples under CO2 atmosphere revealed the presence of multiple configurations of carbonate in the asymmetric O–C–O stretching region with peak splittings of ∼100 and ∼300 cm–1 correlated to the mon...