Understanding the CO Oxidation on Pt Nanoparticles Supported on MOFs by Operando XPS. Issue 19 (13th August 2018)

• Record Type: Journal Article
• Authors: Vakili, Reza; Gibson, Emma K.; Chansai, Sarayute; Xu, Shaojun; Al‐Janabi, Nadeen; Wells, Peter P.; Hardacre, Christopher; Walton, Alex; Fan, Xiaolei
• Is Part Of: ChemCatChem. Volume 10:Issue 19(2018)
• Page Start: 4238
• Page End: 4242
• Publication Date: 2018-08-13
• Subjects: Metal-Organic Frameworks (MOFs) -- Pt Catalysts -- Operando Near Ambient Pressure XPS (NAP-XPS) -- CO Oxidation -- Confinement Effect; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.201801067
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: 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 operando the CO oxidation on Pt@MOFs (UiO‐67) and Pt@ZrO2 catalysts, revealing the same Pt surface dynamics under the stoichiometric CO/O2 ambient at 3 mbar. Upon the ignition at ca . 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@ZrO2 catalyst with ca . 28 % drop in the T 50% 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. Abstract : Successful operando : the comparative study of Pt catalysts supported on Zr UiO‐67 MOF and ZrO2 in stoichiometric CO oxidation using operando NAP‐XPS reveals the Pt metal (rather than oxides) as the active phase and the surface dynamics of the active phase during the catalysis. UiO‐67 MOF showed excellent sinter‐resistance ability in CO oxidation, leading to the outstanding stability over the reference Pt supported on ZrO2 catalyst, which was confirmed by the light‐off experiments under plug‐flow conditions.