Kinetics of Lifetime Changes in Bimetallic Nanocatalysts Revealed by Quick X-ray Absorption Spectroscopy

Matthias Filez; Hilde Poelman; Evgeniy A Redekop; Vladimir V Galvita; Konstantinos Alexopoulos; Maria Meledina; Ranjith K Ramachandran; Jolien Dendooven; Christophe Detavernier; Gustaaf Van Tendeloo; Olga V Safonova; Maarten Nachtegaal; Bert M Weckhuysen; Guy B Marin

doi:10.1002/anie.201806447

Kinetics of Lifetime Changes in Bimetallic Nanocatalysts Revealed by Quick X-ray Absorption Spectroscopy

Angew Chem Int Ed Engl. 2018 Sep 17;57(38):12430-12434. doi: 10.1002/anie.201806447. Epub 2018 Aug 28.

Authors

Matthias Filez^{1

2}, Hilde Poelman¹, Evgeniy A Redekop^{1

3}, Vladimir V Galvita¹, Konstantinos Alexopoulos^{1

4}, Maria Meledina^{5

6}, Ranjith K Ramachandran⁷, Jolien Dendooven⁷, Christophe Detavernier⁷, Gustaaf Van Tendeloo⁵, Olga V Safonova⁸, Maarten Nachtegaal⁸, Bert M Weckhuysen⁹, Guy B Marin¹

Affiliations

¹ Laboratory for Chemical Technology, Ghent University, Technologiepark 914, 9052, Ghent, Belgium.
² Current address: Inorganic Chemistry and Catalysis group, Utrecht University, Universiteitsweg 99, 3584CG, Utrecht, The Netherlands.
³ Current address: Centre for Materials Science and Nanotechnology, University of Oslo, P.O box 1126 Blindern, 0318, Oslo, Norway.
⁴ Current address: Department of Chemical & Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA.
⁵ Electron microscopy for materials science, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium.
⁶ Current address: Central Facility for Electron Microscopy, RWTH Aachen, Ahornstraße 55, 52074, Aachen, Germany.
⁷ Conformal Coatings of Nanomaterials group, Ghent University, Krijgslaan 281/S1, 9000, Ghent, Belgium.
⁸ Paul Scherrer Institute, 5232, Villigen PSI, Switzerland.
⁹ Inorganic Chemistry and Catalysis group, Utrecht University, Universiteitsweg 99, 3584CG, Utrecht, The Netherlands.

Abstract

Alloyed metal nanocatalysts are of environmental and economic importance in a plethora of chemical technologies. During the catalyst lifetime, supported alloy nanoparticles undergo dynamic changes which are well-recognized but still poorly understood. High-temperature O₂ -H₂ redox cycling was applied to mimic the lifetime changes in model Pt₁₃ In₉ nanocatalysts, while monitoring the induced changes by in situ quick X-ray absorption spectroscopy with one-second resolution. The different reaction steps involved in repeated Pt₁₃ In₉ segregation-alloying are identified and kinetically characterized at the single-cycle level. Over longer time scales, sintering phenomena are substantiated and the intraparticle structure is revealed throughout the catalyst lifetime. The in situ time-resolved observation of the dynamic habits of alloyed nanoparticles and their kinetic description can impact catalysis and other fields involving (bi)metallic nanoalloys.

Keywords: alloying segregation; bimetallic nanoparticles; in situ time-resolved X-ray absorption spectroscopy; kinetics; oxidation-reduction.

Abstract

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