Kinetics and mechanism of catalytic reduction of U(VI) with hydrazine on platinum catalysts in nitric acid media
| العنوان: | Kinetics and mechanism of catalytic reduction of U(VI) with hydrazine on platinum catalysts in nitric acid media |
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| المؤلفون: | Xiao-teng Zhang, Shuai Hao, Fei-fei Tang, Bin Li, Xian-ming Zhou, Li-sheng Liu, Liang-shu Xia |
| المصدر: | Chinese Journal of Chemical Physics. 35:813-822 |
| بيانات النشر: | AIP Publishing, 2022. |
| سنة النشر: | 2022 |
| مصطلحات موضوعية: | Physical and Theoretical Chemistry |
| الوصف: | The kinetics of U(IV) produced by hydrazine reduction of U(VI) with platinum as a catalyst in nitric acid media was studied to reveal the reaction mechanism and optimize the reaction process. Electron spin resonance (ESR) was used to determine the influence of nitric acid oxidation. The effects of nitric acid, hydrazine, U(VI) concentration, catalyst dosage and temperature on the reaction rate were also studied. In addition, the simulation of the reaction process was performed using density functional theory. The results show that the influence of oxidation on the main reaction is limited when the concentration of nitric acid is below 0.5 mol/L. The reaction kinetics equation below the concentration of 0.5 mol/L is found as: −d c(UO22+)/d t= kc0.5323(UO22+) c0.2074(N2H5+) c−0.2009(H+). When the temperature is 50 ◦C, and the solid/liquid ratio r is 0.0667 g/mL, the reaction kinetics constant is k=0.00199 (mol/L)0.4712/min. Between 20 ◦C and 80 ◦C, the reaction rate gradually increases with the increase of temperature, and changes from chemically controlled to diffusion-controlled. The simulations of density functional theory give further insight into the influence of various factors on the reaction process, with which the reaction mechanisms are determined according to the reaction kinetics and the simulation results. |
| تدمد: | 2327-2244 1674-0068 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_________::6f512778fcafd2191eed2d359602c84fTest https://doi.org/10.1063/1674-0068/cjcp2103053Test |
| رقم الانضمام: | edsair.doi...........6f512778fcafd2191eed2d359602c84f |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 23272244 16740068 |
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