Monolayer Support Control and Precise Colloidal Nanocrystals Demonstrate Metal–Support Interactions in Heterogeneous Catalysts. Issue 44 (17th September 2021)

• Record Type: Journal Article
• Authors: Goodman, Emmett D.; Asundi, Arun S.; Hoffman, Adam S.; Bustillo, Karen C.; Stebbins, Jonathan F.; Bare, Simon R.; Bent, Stacey F.; Cargnello, Matteo
• Is Part Of: Advanced materials. Volume 33:Issue 44(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-09-17
• Subjects: atomic layer deposition -- colloidal nanocrystals -- heterogeneous catalysis -- metal–support interactions -- monolayer control; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202104533
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Electronic and geometric interactions between active and support phases are critical in determining the activity of heterogeneous catalysts, but metal–support interactions are challenging to study. Here, it is demonstrated how the combination of the monolayer‐controlled formation using atomic layer deposition (ALD) and colloidal nanocrystal synthesis methods leads to catalysts with sub‐nanometer precision of active and support phases, thus allowing for the study of the metal–support interactions in detail. The use of this approach in developing a fundamental understanding of support effects in Pd‐catalyzed methane combustion is demonstrated. Uniform Pd nanocrystals are deposited onto Al2 O3 /SiO2 spherical supports prepared with control over morphology and Al2 O3 layer thicknesses ranging from sub‐monolayer to a ≈4 nm thick uniform coating. Dramatic changes in catalytic activity depending on the coverage and structure of Al2 O3 situated at the Pd/Al2 O3 interface are observed, with even a single monolayer of alumina contributing an order of magnitude increase in reaction rate. By building the Pd/Al2 O3 interface up layer‐by‐layer and using uniform Pd nanocrystals, this work demonstrates the importance of controlled and tunable materials in determining metal–support interactions and catalyst activity. Abstract : Interactions between coexisting metal and metal oxide phases determine the properties of heterogeneous catalysts. Atomic layer deposition and colloidal nanocrystal synthesis are combined to precisely control catalyst properties with sub‐nanometer precision. Significant enhancements are observed in methane combustion activity after modification of SiO2 support with only one monolayer of Al2 O3, and surface versus bulk contributions of metal–support interactions are explored.