|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Environmental Science / Faculty of Environmental Earth Science >
Peer-reviewed Journal Articles, etc >
Drastic change in selectivity caused by addition of oxygen to the hydrogen stream for the hydrogenation of nitrite in water over a supported platinum catalyst
| Title: | Drastic change in selectivity caused by addition of oxygen to the hydrogen stream for the hydrogenation of nitrite in water over a supported platinum catalyst |
| Authors: | Hirayama, Jun Browse this author | | Yasuda, Kei-ichiro Browse this author | | Misu, Sayaka Browse this author | | Otomo, Ryoichi Browse this author →KAKEN DB | | Kamiya, Yuichi Browse this author →KAKEN DB |
| Issue Date: | 7-Aug-2019 |
| Publisher: | Royal Society of Chemistry |
| Journal Title: | Catalysis science and technology |
| Volume: | 9 |
| Issue: | 15 |
| Start Page: | 4017 |
| End Page: | 4022 |
| Publisher DOI: | 10.1039/c9cy00999j |
| Abstract: | In the present study, we investigated the influence of the addition of O₂ to the H₂ reactant stream during the hydrogenation of NO₂⁻ in water on the catalytic performances of Al₂O₃-supported precious metal catalysts including Pd, Pt, Ir, Rh, and Ru with 0.3 mmol g-¹ of the metal. Pd/Al₂O₃ showed high selectivity for N₂ irrespective of the presence and absence of O₂, and Rh and Ru/Al₂O₃ were inactive towards the hydrogenation of NO₂⁻ even in the absence of O₂. In contrast, while Pt/Al₂O₃ showed high selectivity for NH₃ (90%) in the absence of O₂ (P-H2 = 0.2 atm and P-O2 = 0 atm), the product drastically changed to N₂ with 93% selectivity when O₂ was added (P-H2 = 0.2 atm and P-O2 = 0.1 atm). Since Pt/Al₂O₃ was completely inactive towards the oxidation of NH₃ with O₂ in water under the reaction conditions, oxidative decomposition of the formed NH₃ was not the reason for the high selectivity for N₂ in the presence of O₂. Kinetic analysis of the reaction in the absence and presence of O₂ and studies on the effects of the Pt size suggested that hydrogen atoms activated on the Pt particles were mainly consumed by O₂ upon H₂O formation in the presence of O₂. We concluded that the inactivation of the Pt sites active for NH₃ formation and furthermore the change in the function of the sites to N₂ formation caused by the O₂ addition lead to the drastic change in the selectivity from NH₃ to N₂ in the presence of O₂. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/79051 |
| Appears in Collections: | 環境科学院・地球環境科学研究院 (Graduate School of Environmental Science / Faculty of Environmental Earth Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 神谷 裕一
|
