CO<sub>2</sub> Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining Step
Cu-based catalysts are promising for CO oxidation applications with catalyst deactivation being a major barrier. We start with a CuO/Al<sub>2</sub>O<sub>3</sub> catalyst and find that while the CO conversion decreases, CO<sub>2</sub> accumulates and the average Cu...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-05-01
|
| Series: | Catalysts |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4344/11/6/654 |
| _version_ | 1797533063134052352 |
|---|---|
| author | Kai Cheng Songjian Zhao Jiazheng Ren Haoran Li Yongsheng Chen |
| author_facet | Kai Cheng Songjian Zhao Jiazheng Ren Haoran Li Yongsheng Chen |
| author_sort | Kai Cheng |
| collection | DOAJ |
| description | Cu-based catalysts are promising for CO oxidation applications with catalyst deactivation being a major barrier. We start with a CuO/Al<sub>2</sub>O<sub>3</sub> catalyst and find that while the CO conversion decreases, CO<sub>2</sub> accumulates and the average Cu chemical state stays the same. It suggests CO<sub>2</sub> self-poisoning, i.e., CO<sub>2</sub> desorption is the rate-determining step. Subsequently, experiments are performed to prove this hypothesis by showing (1) CO<sub>2</sub> adsorption inhibits O<sub>2</sub> adsorption, (2) complete desorption of CO<sub>2</sub> regenerate the catalyst, (3) pre-adsorbed CO<sub>2</sub> quenches catalyst activity which recovers during the reaction and (4) the apparent activation energy is consistent with CO<sub>2</sub> desorption. It is further evidenced by using a stronger CO<sub>2</sub> adsorbing support CeO<sub>2</sub> to speed up CO<sub>2</sub> desorption from the CuO sites resulting in a superior CuO/CeO<sub>2</sub> catalyst. It provides an example for experimentally deciding and speeding up the rate-determining step in a catalytic reaction. |
| first_indexed | 2024-03-10T11:09:13Z |
| format | Article |
| id | doaj.art-4fd44573e4a3426e9fbd7d82d0457638 |
| institution | Directory Open Access Journal |
| issn | 2073-4344 |
| language | English |
| last_indexed | 2024-03-10T11:09:13Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Catalysts |
| spelling | doaj.art-4fd44573e4a3426e9fbd7d82d04576382023-11-21T20:53:42ZengMDPI AGCatalysts2073-43442021-05-0111665410.3390/catal11060654CO<sub>2</sub> Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining StepKai Cheng0Songjian Zhao1Jiazheng Ren2Haoran Li3Yongsheng Chen4Energy and Catalysis Laboratory, Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ChinaEnergy and Catalysis Laboratory, Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ChinaEnergy and Catalysis Laboratory, Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ChinaEnergy and Catalysis Laboratory, Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ChinaEnergy and Catalysis Laboratory, Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ChinaCu-based catalysts are promising for CO oxidation applications with catalyst deactivation being a major barrier. We start with a CuO/Al<sub>2</sub>O<sub>3</sub> catalyst and find that while the CO conversion decreases, CO<sub>2</sub> accumulates and the average Cu chemical state stays the same. It suggests CO<sub>2</sub> self-poisoning, i.e., CO<sub>2</sub> desorption is the rate-determining step. Subsequently, experiments are performed to prove this hypothesis by showing (1) CO<sub>2</sub> adsorption inhibits O<sub>2</sub> adsorption, (2) complete desorption of CO<sub>2</sub> regenerate the catalyst, (3) pre-adsorbed CO<sub>2</sub> quenches catalyst activity which recovers during the reaction and (4) the apparent activation energy is consistent with CO<sub>2</sub> desorption. It is further evidenced by using a stronger CO<sub>2</sub> adsorbing support CeO<sub>2</sub> to speed up CO<sub>2</sub> desorption from the CuO sites resulting in a superior CuO/CeO<sub>2</sub> catalyst. It provides an example for experimentally deciding and speeding up the rate-determining step in a catalytic reaction.https://www.mdpi.com/2073-4344/11/6/654catalyst deactivationCO<sub>2</sub> self-poisoningCO oxidationrate-determining stepCuO catalysts |
| spellingShingle | Kai Cheng Songjian Zhao Jiazheng Ren Haoran Li Yongsheng Chen CO<sub>2</sub> Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining Step Catalysts catalyst deactivation CO<sub>2</sub> self-poisoning CO oxidation rate-determining step CuO catalysts |
| title | CO<sub>2</sub> Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining Step |
| title_full | CO<sub>2</sub> Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining Step |
| title_fullStr | CO<sub>2</sub> Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining Step |
| title_full_unstemmed | CO<sub>2</sub> Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining Step |
| title_short | CO<sub>2</sub> Self-Poisoning and Its Mitigation in CuO Catalyzed CO Oxidation: Determining and Speeding up the Rate-Determining Step |
| title_sort | co sub 2 sub self poisoning and its mitigation in cuo catalyzed co oxidation determining and speeding up the rate determining step |
| topic | catalyst deactivation CO<sub>2</sub> self-poisoning CO oxidation rate-determining step CuO catalysts |
| url | https://www.mdpi.com/2073-4344/11/6/654 |
| work_keys_str_mv | AT kaicheng cosub2subselfpoisoninganditsmitigationincuocatalyzedcooxidationdeterminingandspeedinguptheratedeterminingstep AT songjianzhao cosub2subselfpoisoninganditsmitigationincuocatalyzedcooxidationdeterminingandspeedinguptheratedeterminingstep AT jiazhengren cosub2subselfpoisoninganditsmitigationincuocatalyzedcooxidationdeterminingandspeedinguptheratedeterminingstep AT haoranli cosub2subselfpoisoninganditsmitigationincuocatalyzedcooxidationdeterminingandspeedinguptheratedeterminingstep AT yongshengchen cosub2subselfpoisoninganditsmitigationincuocatalyzedcooxidationdeterminingandspeedinguptheratedeterminingstep |