A Polycrystalline Pd Surface Studied by Two-Dimensional Surface Optical Reflectance during CO Oxidation: Bridging the Materials Gap

Journal Article · 18 December 2023 · ACS Applied Materials and Interfaces

DOI: https://doi.org/10.1021/acsami.3c11341 · OSTI ID:2471761

Pfaff, Sebastian  ^[1]; Larsson, Alfred  ^[2]; Orlov, Dmytro ^[3]; Rämisch, Lisa ^[2]; Gericke, Sabrina M. ^[2]; Lundgren, Edvin  ^[2]; Zetterberg, Johan  ^[2]

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1. Sandia National Laboratories (SNL-CA), Livermore, CA (United States)
2. Lund University, Sölvegatan (Sweden)
3. Lund University, Ole Römers väg (Sweden)

Industrial catalysts are complex materials systems operating in harsh environments. The active parts of the catalysts are nanoparticles that expose different facets with different surface orientations at which the catalytic reactions occur. However, these facets are close to impossible to study in detail under industrially relevant operating conditions. Instead, simpler model systems, such as single crystals with a well-defined surface orientation, have been successfully used to study gas–surface interactions such as adsorption and desorption, surface oxidation, and oxidation/reduction reactions. To more closely mimic the many facets exhibited by nanoparticles and thereby close the so-called materials gap, there has also been a recent move toward using polycrystalline surfaces and curved crystals. However, these studies are limited either by the pressure or spatial resolution at realistic pressures or by the number of surfaces studied simultaneously. In this work, we demonstrate the use of reflectance microscopy to study a vast number of catalytically active surfaces simultaneously under realistic and identical reaction conditions. As a proof of concept, we have conducted an operando experiment to study CO oxidation over a Pd polycrystal, where the polycrystalline surface acts as a collection of many single-crystal surfaces. Finally, we visualized the resulting data by plotting the reflectivity as a function of surface orientation. We think the techniques and visualization methods introduced in this work will be key toward bridging the materials gap in catalysis.

• Research Organization: Sandia National Laboratories (SNL-CA), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); Knut and Alice Wallenberg foundation (KAW); Swedish Research Council; Swedish Foundation for Strategic Research
• Grant/Contract Number: NA0003525
• OSTI ID: 2471761
• Journal Information: ACS Applied Materials and Interfaces, Journal Name: ACS Applied Materials and Interfaces Journal Issue: 1 Vol. 16; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English