Systematic Identification of Promoters for Methane Oxidation Catalysts Using Size- and Composition-Controlled Pd-Based Bimetallic Nanocrystals
| Autor: | Christopher J. Tassone, Matteo Cargnello, Andrew R. Riscoe, Pedro Martins, Emmett D. Goodman, Liheng Wu, Joshua J. Willis |
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| Rok vydání: | 2017 |
| Předmět: |
Thermal decomposition
Oxide chemistry.chemical_element Nanotechnology 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Metal chemistry.chemical_compound Colloid and Surface Chemistry chemistry Chemical engineering Transition metal Phase (matter) visual_art visual_art.visual_art_medium 0210 nano-technology Bimetallic strip Palladium |
| Zdroj: | Journal of the American Chemical Society. 139:11989-11997 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | Promoters enhance the performance of catalytic active phases by increasing rates, stability, and/or selectivity. The process of identifying promoters is in most cases empirical and relies on testing a broad range of catalysts prepared with the random deposition of active and promoter phases, typically with no fine control over their localization. This issue is particularly relevant in supported bimetallic systems, where two metals are codeposited onto high-surface area materials. We here report the use of colloidal bimetallic nanocrystals to produce catalysts where the active and promoter phases are colocalized to a fine extent. This strategy enables a systematic approach to study the promotional effects of several transition metals on palladium catalysts for methane oxidation. In order to achieve these goals, we demonstrate a single synthetic protocol to obtain uniform palladium-based bimetallic nanocrystals (PdM, M = V, Mn, Fe, Co, Ni, Zn, Sn, and potentially extendable to other metal combinations) with a wide variety of compositions and sizes based on high-temperature thermal decomposition of readily available precursors. Once the nanocrystals are supported onto oxide materials, thermal treatments in air cause segregation of the base metal oxide phase in close proximity to the Pd phase. We demonstrate that some metals (Fe, Co, and Sn) inhibit the sintering of the active Pd metal phase, while others (Ni and Zn) increase its intrinsic activity compared to a monometallic Pd catalyst. This procedure can be generalized to systematically investigate the promotional effects of metal and metal oxide phases for a variety of active metal-promoter combinations and catalytic reactions. |
| Databáze: | OpenAIRE |
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