Stability enhancement for silver catalyst in ethylene epoxidation by support treatment
The high cost of the silver catalyst for ethylene epoxidation to ethylene oxide (EO) requires the development of the catalyst with a lower silver loading and a longer catalyst life span. Preventing silver particles from clustering could help maintain the activity for EO. In this work, we applied NH4...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-05-01
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| Series: | Catalysis Communications |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1566736723000717 |
| _version_ | 1797832769193115648 |
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| author | Chengyang He Xiaojun Lu Yiwen Liu Zhiguo Yan Rui Zhang Xinying Liu |
| author_facet | Chengyang He Xiaojun Lu Yiwen Liu Zhiguo Yan Rui Zhang Xinying Liu |
| author_sort | Chengyang He |
| collection | DOAJ |
| description | The high cost of the silver catalyst for ethylene epoxidation to ethylene oxide (EO) requires the development of the catalyst with a lower silver loading and a longer catalyst life span. Preventing silver particles from clustering could help maintain the activity for EO. In this work, we applied NH4F solution for an etching-treatment of the α-Al2O3 to improve the roughness of its internal surface before loading silver. The catalyst with etching-treated support showed close activity and EO selectivity initially when compared to the one that was prepared with untreated support while in the meantime its stability was greatly enhanced. The silver catalyst with untreated support lost its activity for EO to nearly zero after 22 days of test at 260 °C and 2 MPa(g), while the one with etching-treated support maintained stable activity from day 10 to 22. The detailed morphology study for the catalysts suggests that the loss of EO activity is mainly attributed to the migration of silver particles from the plane of the support flakes to the gaps that formed by the flakes and deep oxidation of ethylene was largely enhanced by the active sites crowded in the flake gaps. The support treatment effectively slowed down the formation of larger silver clusters and helped maintain a better dispersion of the silver particles on the support. |
| first_indexed | 2024-04-09T14:13:08Z |
| format | Article |
| id | doaj.art-6fc74d9d4fe449bb9e73f1d1568559f1 |
| institution | Directory Open Access Journal |
| issn | 1873-3905 |
| language | English |
| last_indexed | 2024-04-09T14:13:08Z |
| publishDate | 2023-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Catalysis Communications |
| spelling | doaj.art-6fc74d9d4fe449bb9e73f1d1568559f12023-05-06T04:37:09ZengElsevierCatalysis Communications1873-39052023-05-01178106669Stability enhancement for silver catalyst in ethylene epoxidation by support treatmentChengyang He0Xiaojun Lu1Yiwen Liu2Zhiguo Yan3Rui Zhang4Xinying Liu5School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, ChinaSchool of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China; Corresponding author.School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, ChinaSchool of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, ChinaSchool of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, ChinaInstitute for the Development of Energy for African Sustainability, University of South Africa, Johannesburg 1710, South Africa.The high cost of the silver catalyst for ethylene epoxidation to ethylene oxide (EO) requires the development of the catalyst with a lower silver loading and a longer catalyst life span. Preventing silver particles from clustering could help maintain the activity for EO. In this work, we applied NH4F solution for an etching-treatment of the α-Al2O3 to improve the roughness of its internal surface before loading silver. The catalyst with etching-treated support showed close activity and EO selectivity initially when compared to the one that was prepared with untreated support while in the meantime its stability was greatly enhanced. The silver catalyst with untreated support lost its activity for EO to nearly zero after 22 days of test at 260 °C and 2 MPa(g), while the one with etching-treated support maintained stable activity from day 10 to 22. The detailed morphology study for the catalysts suggests that the loss of EO activity is mainly attributed to the migration of silver particles from the plane of the support flakes to the gaps that formed by the flakes and deep oxidation of ethylene was largely enhanced by the active sites crowded in the flake gaps. The support treatment effectively slowed down the formation of larger silver clusters and helped maintain a better dispersion of the silver particles on the support.http://www.sciencedirect.com/science/article/pii/S1566736723000717Ethylene epoxidationEthylene oxideSilver catalystStability in activity |
| spellingShingle | Chengyang He Xiaojun Lu Yiwen Liu Zhiguo Yan Rui Zhang Xinying Liu Stability enhancement for silver catalyst in ethylene epoxidation by support treatment Catalysis Communications Ethylene epoxidation Ethylene oxide Silver catalyst Stability in activity |
| title | Stability enhancement for silver catalyst in ethylene epoxidation by support treatment |
| title_full | Stability enhancement for silver catalyst in ethylene epoxidation by support treatment |
| title_fullStr | Stability enhancement for silver catalyst in ethylene epoxidation by support treatment |
| title_full_unstemmed | Stability enhancement for silver catalyst in ethylene epoxidation by support treatment |
| title_short | Stability enhancement for silver catalyst in ethylene epoxidation by support treatment |
| title_sort | stability enhancement for silver catalyst in ethylene epoxidation by support treatment |
| topic | Ethylene epoxidation Ethylene oxide Silver catalyst Stability in activity |
| url | http://www.sciencedirect.com/science/article/pii/S1566736723000717 |
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