Laser‐Induced Formation of Metal–Peroxide Linkages on the Surface of Lanthanum Sesquioxide under Oxygen

Laser irradiation of La2O3 under oxygen at 300–500 °C with the beam of a microprobe Raman spectrometer (λ=325, 514.5, or 632.8 nm) caused the emergence of a peroxide band at ≈840 cm−1 at the expense of the ν band at ≈400 cm−1 with clear isosbestic points at 389 and 558 cm−1 (see picture). This photoexcitation process has implications for laser Raman spectroscopic studies on lanthanide oxide catalysts under working conditions.