Platinum on High-Entropy Aluminate Spinels as Thermally Stable CO Oxidation Catalysts
Thermal degradation is a leading cause of automotive catalyst deactivation. Because high-entropy oxides are uniquely stabilized at high temperatures via an increase in configurational entropy, these materials may offer new mechanisms for preventing the thermal deactivation of precious metal catalyst...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-03-01
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| Series: | Catalysts |
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| Online Access: | https://www.mdpi.com/2073-4344/14/3/211 |
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| author | Christopher Riley Andrew De La Riva Nichole Valdez Ryan Alcala Ping Lu Richard Grant Angelica Benavidez Mark Rodriguez Abhaya Datye Stanley S. Chou |
| author_facet | Christopher Riley Andrew De La Riva Nichole Valdez Ryan Alcala Ping Lu Richard Grant Angelica Benavidez Mark Rodriguez Abhaya Datye Stanley S. Chou |
| author_sort | Christopher Riley |
| collection | DOAJ |
| description | Thermal degradation is a leading cause of automotive catalyst deactivation. Because high-entropy oxides are uniquely stabilized at high temperatures via an increase in configurational entropy, these materials may offer new mechanisms for preventing the thermal deactivation of precious metal catalysts. In this work, we evaluated platinum loaded on simple and high-entropy aluminate spinels (MAl<sub>2</sub>O<sub>4</sub>, where M = Co, Cu, Mg, Ni, or mixtures thereof) in carbon monoxide oxidation before and after aging at 800 °C. Pt supported on all simple spinels showed significant deactivation after thermal aging compared to the fresh samples, with T<sub>90</sub> increasing by at least 60 °C. However, Pt on high-entropy spinels had nearly the same or better activity after aging, with T<sub>90</sub> increasing by only 6 °C at most. During aging and reduction, copper exsolved from the spinel supports and alloyed with platinum. This interaction promoted low temperature oxidation activity, presumably through weakened CO binding, but did not prevent deactivation. On the other hand, Co, Mg, and Ni constituents promoted stronger CO bonding, as evidenced by apparent negative order kinetics and poor activity at low temperatures. High-entropy spinels, containing a variety of active metals, displayed synergetic reactant adsorption capacity and cooperative effects with supported platinum particles, which collectively prevented thermal deactivation. |
| first_indexed | 2024-04-24T18:26:54Z |
| format | Article |
| id | doaj.art-703a9a4e40de415d9f14825d958b96a2 |
| institution | Directory Open Access Journal |
| issn | 2073-4344 |
| language | English |
| last_indexed | 2024-04-24T18:26:54Z |
| publishDate | 2024-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Catalysts |
| spelling | doaj.art-703a9a4e40de415d9f14825d958b96a22024-03-27T13:30:27ZengMDPI AGCatalysts2073-43442024-03-0114321110.3390/catal14030211Platinum on High-Entropy Aluminate Spinels as Thermally Stable CO Oxidation CatalystsChristopher Riley0Andrew De La Riva1Nichole Valdez2Ryan Alcala3Ping Lu4Richard Grant5Angelica Benavidez6Mark Rodriguez7Abhaya Datye8Stanley S. Chou9Sandia National Laboratories, Albuquerque, NM 87185, USADepartment of Chemical and Biological Engineering and Center for Microengineered Materials, University of New Mexico, Albuquerque, NM 87131, USASandia National Laboratories, Albuquerque, NM 87185, USADepartment of Chemical and Biological Engineering and Center for Microengineered Materials, University of New Mexico, Albuquerque, NM 87131, USASandia National Laboratories, Albuquerque, NM 87185, USASandia National Laboratories, Albuquerque, NM 87185, USADepartment of Chemical and Biological Engineering and Center for Microengineered Materials, University of New Mexico, Albuquerque, NM 87131, USASandia National Laboratories, Albuquerque, NM 87185, USADepartment of Chemical and Biological Engineering and Center for Microengineered Materials, University of New Mexico, Albuquerque, NM 87131, USASandia National Laboratories, Albuquerque, NM 87185, USAThermal degradation is a leading cause of automotive catalyst deactivation. Because high-entropy oxides are uniquely stabilized at high temperatures via an increase in configurational entropy, these materials may offer new mechanisms for preventing the thermal deactivation of precious metal catalysts. In this work, we evaluated platinum loaded on simple and high-entropy aluminate spinels (MAl<sub>2</sub>O<sub>4</sub>, where M = Co, Cu, Mg, Ni, or mixtures thereof) in carbon monoxide oxidation before and after aging at 800 °C. Pt supported on all simple spinels showed significant deactivation after thermal aging compared to the fresh samples, with T<sub>90</sub> increasing by at least 60 °C. However, Pt on high-entropy spinels had nearly the same or better activity after aging, with T<sub>90</sub> increasing by only 6 °C at most. During aging and reduction, copper exsolved from the spinel supports and alloyed with platinum. This interaction promoted low temperature oxidation activity, presumably through weakened CO binding, but did not prevent deactivation. On the other hand, Co, Mg, and Ni constituents promoted stronger CO bonding, as evidenced by apparent negative order kinetics and poor activity at low temperatures. High-entropy spinels, containing a variety of active metals, displayed synergetic reactant adsorption capacity and cooperative effects with supported platinum particles, which collectively prevented thermal deactivation.https://www.mdpi.com/2073-4344/14/3/211high entropy oxidespinelCO oxidationaging |
| spellingShingle | Christopher Riley Andrew De La Riva Nichole Valdez Ryan Alcala Ping Lu Richard Grant Angelica Benavidez Mark Rodriguez Abhaya Datye Stanley S. Chou Platinum on High-Entropy Aluminate Spinels as Thermally Stable CO Oxidation Catalysts Catalysts high entropy oxide spinel CO oxidation aging |
| title | Platinum on High-Entropy Aluminate Spinels as Thermally Stable CO Oxidation Catalysts |
| title_full | Platinum on High-Entropy Aluminate Spinels as Thermally Stable CO Oxidation Catalysts |
| title_fullStr | Platinum on High-Entropy Aluminate Spinels as Thermally Stable CO Oxidation Catalysts |
| title_full_unstemmed | Platinum on High-Entropy Aluminate Spinels as Thermally Stable CO Oxidation Catalysts |
| title_short | Platinum on High-Entropy Aluminate Spinels as Thermally Stable CO Oxidation Catalysts |
| title_sort | platinum on high entropy aluminate spinels as thermally stable co oxidation catalysts |
| topic | high entropy oxide spinel CO oxidation aging |
| url | https://www.mdpi.com/2073-4344/14/3/211 |
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