Precisely Engineered Supported Gold Clusters as a Stable Catalyst for Propylene Epoxidation
| Autor: | Marc-Olivier Coppens, Nidhi Kapil, Panagiotis Trogadas, Michael M. Nigra, Fabio Cardinale, Tobias Weissenberger, T. Alexander Nijhuis |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Hydrogen propylene chemistry.chemical_element General Chemistry General Medicine gold Heterogeneous catalysis Catalysis O2 plasma chemistry X-ray photoelectron spectroscopy Chemical engineering Heterogeneous Catalysis epoxidation Particle size catalyst stability Selectivity High-resolution transmission electron microscopy Research Articles Research Article |
| Zdroj: | Angewandte Chemie (International Ed. in English) |
| ISSN: | 1521-3773 |
| Popis: | Designing a stable and selective catalyst with high H2 utilisation is of pivotal importance for the direct gas‐phase epoxidation of propylene. This work describes a facile one‐pot methodology to synthesise ligand‐stabilised sub‐nanometre gold clusters immobilised onto a zeolitic support (TS‐1) to engineer a stable Au/TS‐1 catalyst. A non‐thermal O2 plasma technique is used for the quick removal of ligands with limited increase in particle size. Compared to untreated Au/TS‐1 catalysts prepared using the deposition precipitation method, the synthesised catalyst exhibits improved catalytic performance, including 10 times longer lifetime (>20 days), increased PO selectivity and hydrogen efficiency in direct gas phase epoxidation. The structure‐stability relationship of the catalyst is illustrated using multiple characterisation techniques, such as XPS, 31P MAS NMR, DR‐UV/VIS, HRTEM and TGA. It is hypothesised that the ligands play a guardian role in stabilising the Au particle size, which is vital in this reaction. This strategy is a promising approach towards designing a more stable heterogeneous catalyst. A stable and selective Au/TS‐1 catalyst is synthesised for direct gas phase epoxidation of propylene to propylene oxide, a key commodity chemical. The synthesis methodology is highly versatile for obtaining a stable, supported gold catalyst. The stabilising ligands play an important role in providing enhanced stability to the Au nanoparticles. |
| Databáze: | OpenAIRE |
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