Fig. 5: Characterisation of CO^* covered catalyst via DRIFTS, TAP, and kinetic modelling.

a DRIFT spectra for CO adsorption on the CO^*-covered 2 nm Pt/SiO₂ catalyst where CO^* was preadsorbed at 35, 100, 200, and 350 °C. The spectra were obtained after cooling the catalyst to 35 °C. All DRIFTS measurements were acquired at 35 °C which avoids the influence of temperature on vibrational features⁸⁰. b Illustration for adsorbed CO^* sites (well-coordinated and under-coordinated) on the surface of a model Pt nanoparticle (regular, truncated octahedron; 586 atoms; ~2.17 nm-size). c Integrated Ar normalised exit flux of m/z = 44 (CO₂) during TPO experiments on the CO^*-covered Pt/SiO₂ catalyst where CO^* was preadsorbed at 25, 100, 200, and 350 °C. For TPO experiments, the CO^* was preadsorbed at 25–350 °C on the catalyst and the catalyst was cooled to 25 °C. Then O₂ was repeatedly pulsed over the catalyst while being linearly heated to 350 °C at 8 °C/min. d–g Deconvoluted CO₂ production pathways and CO₂ production pathway ratios calculated using the regressed kinetic model (MZTRT) for the TPO experiments where CO^* was preadsorbed at (d) 25, (e) 100, (f) 200, (g) 350 °C.