Understanding the CO Oxidation on Pt Nanoparticles Supported on MOFs by XPS.

Metal-organic frameworks (MOFs) are playing a key role in developing the next generation of heterogeneous catalysts. In this work, near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) is applied to study in the CO oxidation on Pt@MOFs (UiO-67) and Pt@ZrO catalysts, revealing the same Pt surface dynamics under the stoichiometric CO/O ambient at 3 mbar. Upon the ignition at . 200 °C, the signature Pt binding energy (BE) shift towards the lower BE (from 71.8 to 71.2 eV) is observed for all catalysts, confirming metallic Pt nanoparticles (NPs) as the active phase. Additionally, the plug-flow light-off experiments show the superior activity of the Pt@MOFs catalyst in CO oxidation than the control Pt@ZrO catalyst with . 28 % drop in the light-off temperature, as well as high stability, due to their sintering-resistance feature. These results provide evidence that the uniqueness of MOFs as the catalyst supports lies in the structural confinement effect.