Synthesis of perovskite polyhedron nanocrystals with equivalent facets and the controlled growth of Pt nanoparticles with differing surface concentration of oxidized Pt⁴⁺/Pt²⁺ species

Journal Article · Wed May 04 00:00:00 EDT 2022 · Catalysis Today

DOI:https://doi.org/10.1016/j.cattod.2022.05.002· OSTI ID:1976912

Hu, Linhua ^[1]; Poeppelmeier, Kenneth R. ^[1]

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1. Northwestern Univ., Evanston, IL (United States). Center for Catalysis and Surface Science

Co-existence of different surfaces in traditional polycrystalline heterogeneous catalysts imposes a challenge to induce different kinds of catalytic species and average reactivity. Supported metal/oxide model catalyst designed with equivalent well-defined surfaces and active species provides an opportunity to control the uniformity, maintain efficient activity, and understand catalytic mechanisms at the atomic and molecular levels. Herein, sub-20 nm perovskite-structure BaTiO₃ polyhedron nanocuboids and Zr-substituted rhombic dodecahedron nanocrystals were synthesized and employed as the oxide support for the subsequent uniform growth of 1–2 nm Pt nanoparticles. These Pt nanoparticles were well dispersed on the 12 equivalent (110) facets of BaTi_0.75Zr_0.25O₃ rhombic dodecahedra and on the 6 equivalent (100) facets of BaTiO₃ nanocuboids. The main active centers on the Pt/BaTi_0.75Zr_0.25O₃ catalysts in the oxidized surface layer of Pt (111) facets are Pt⁴⁺ versus Pt²⁺, which is in contrast to the oxidized surface layer of the Pt (100) facets on the Pt/BaTiO₃ cuboids where there are a greater number of Pt²⁺ species. Compared with Pt/BaTiO₃ nanocuboids, the Pt/BaTi_0.75Zr_0.25O₃ catalysts demonstrated higher CO catalytic oxidation activity with a lower apparent Arrhenius activation energy. Finally, this work advances our ability to synthesize metal/oxide model catalyst that offer equivalent facets and highly uniform active centers with reasonable surface area in order to gain insight in reaction mechanisms.

• Research Organization: Northwestern Univ., Evanston, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: FG02-03ER15457
• OSTI ID: 1976912
• Journal Information: Catalysis Today, Vol. 402, Issue C; ISSN 0920-5861
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Chemistry
Engineering
Perovskite nanopolyhedra
Equivalent facets
Pt nanoparticle
Crystal plane effect
CO oxidation
Nonmetallic active species