不同酸碱体系中Pt/SiO_(2)催化肼分解产生自由基  

Free Radical Generation From Hydrazine Decomposition Catalyzed by Pt/SiO_(2) in Different Acid-Base Systems

作　　者：李斌[1] 郝帅 张秋月[1] 夏良树[2] 何辉[1] LI Bin;HAO Shuai;ZHANG Qiu-yue;XIA Liang-shu;HE Hui(China Institute of Atomic Energy,P.O.Box 275(88),Beijing 102413,China;School of Nuclear Science and Technology,University of South China,Hengyang 421001,China)

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413 [2]南华大学核科学技术学院,湖南衡阳421001

出　　处：《核化学与放射化学》2024年第1期54-59,I0006,共7页Journal of Nuclear and Radiochemistry

摘　　要：采用电子自旋共振(electron spin resonance spectroscopy, ESR)法,探讨高氯酸体系和氢氧化钠体系中H^(+)浓度与OH-浓度对催化剂催化肼断键及断键产生的自由基的状态及行为的影响,明确了酸碱体系下Pt/SiO_(2)催化肼分解产生自由基的差异。结果表明:碱性体系中,随着OH-浓度升高,N-H断键速率显著升高,肼分解以氢解反应为主;酸性体系中,在pH=6.9到pH=1.1范围内,随着H^(+)浓度升高,N-N断键速率急速升高并远大于N-H断键速率,在pH<1.1范围内,随着H^(+)浓度升高,N-H断键速率和N-N断键速率均快速下降。在酸碱变化过程中,N-H断键起着主导作用,决定了肼分解速率,随着酸度升高,N-H断键速率下降,肼分解速率下降。Electron spin resonance spectroscopy(ESR)was used to investigate the effects of hydrogen ion concentration and hydroxide concentration in perchloric acid system and sodium hydroxide system on the state and behavior of free radicals generated by hydrazine bond breaking catalyzed by catalysts.The difference of free radicals generated by Pt/SiO_(2) catalyzed hydrazine decomposition in acid-base system was determined.The results show that in the alkaline system,with the increase of hydroxide concentration,the N-H bond breaking rate increases significantly,and the hydrolysis reaction is the main decomposition reaction.In acidic systems,with the increase of hydrogen ion concentration in the pH range from 6.9 to 1.1,the N-N bond breaking rate increases rapidly and is much higher than the N-H bond breaking rate.In the range of pH<1.1,with the increase of hydrogen ion concentration,both the N-H and N-N bond breaking rates decrease rapidly.In the process of acid-base change,the N-H bond breaking plays a leading role in determining the decomposition rate of hydrazine.With the increase of acidity,the N-H bond breaking rate decreases,and the decomposition rate decreases as well.

关 键 词：肼 催化 ESR 自由基 

分 类 号：TL241.1[核科学技术—核燃料循环与材料]