fig4

Figure 4. (A and B) EPR spectra of zeolite series samples (TS, TS@TiO₂, 0.2Pd-TS, 0.2Pd -TS@TiO₂) before and after adding light in oxygen-saturated ultrapure water; (C) O₂-TPD and (D) CH₄-TPD profiles of TS, Pd-TS, TS@TiO₂, Pd-TS@TiO₂. In situ DRIFTS spectra of 0.2Pd-TS@TiO₂ catalyst (E) in the dark and (F) under light illumination in CH₄ + O₂ + H₂O atmosphere. EPR: Electron paramagnetic resonance; TS: titanium silicalite; TPD: temperature-programmed desorption; DRIFTS: diffuse reflectance infrared Fourier-transform spectroscopy.