物理化学学报 >> 2016, Vol. 32 >> Issue (12): 2891-2897.doi: 10.3866/PKU.WHXB201609133

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立方体纳米氧化亚铜反应动力学的理论及实验研究

汤焕丰1,黄在银1,2,3,*(),肖明1,梁敏1,陈栎莹1   

  1. 1 广西民族大学化学化工学院,南宁530006
    2 广西民族大学,广西林产化学与工程重点实验室,南宁530006
    3 广西高校食品安全与药物分析化学重点实验室,南宁530006
  • 收稿日期:2016-08-10 发布日期:2016-11-30
  • 通讯作者: 黄在银 E-mail:huangzaiyin@163.com
  • 基金资助:
    国家自然科学基金(21273050,21573048)

An Investigation into the Reaction Kinetics of Cubic Nano-Cu2O in Theory and Experiment

Huan-Feng TANG1,Zai-Yin HUANG1,2,3,*(),Ming XIAO1,Min LIANG1,Li-Ying CHEN1   

  1. 1 College of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning 530006, P. R. China
    2 Key Laboratory of Forest Chemistry and Engineering, Guangxi University for Nationalities, Nanning 530006, P. R. China
    3 Guangxi Colleges and Universities Key Laboratory of Food Safety and Pharmaceutical Analytical Chemistry, Nanning 530006, P. R. China
  • Received:2016-08-10 Published:2016-11-30
  • Contact: Zai-Yin HUANG E-mail:huangzaiyin@163.com
  • Supported by:
    the National Natural Science Foundation of China(21273050,21573048)

摘要:

为了探究纳米多相反应过程的动力学行为,本文通过液相还原法可控合成了粒度为55 nm的立方体氧化亚铜(Cu2O)。基于纳米与块体Cu2O的区别,采用原位微量热技术获取Cu2O体系与HNO3反应过程的热动力学精细信息,结合热动力学原理及动力学过渡态理论计算得到Cu2O反应动力学参数,并建立立方体动力学模型讨论并佐证动力学实验结果。结果表明,纳米Cu2O的反应速率常数大于块体,而表观活化能、指前因子、活化焓、活化熵和活化Gibbs自由能均小于块体;随着温度的升高,纳米Cu2O的反应速率常数和活化Gibbs自由能均增大。动力学模型表明影响反应动力学参数的主要因素为:偏摩尔表面焓影响表观活化能,偏摩尔表面熵影响指前因子,偏摩尔表面Gibbs自由能影响反应速率常数。本文为纳米材料多相反应动力学参数的获取和分析应用提供了一种普适的理论模型和实验方法。

关键词: 原位微量热技术, 反应动力学, 动力学模型, 纳米材料, 立方体Cu2O

Abstract:

To investigate the kinetic behaviors of nanoparticle heterogeneous reactions, we introduced a liquidphase reduction method to control the synthesis of cubic cuprous oxide with a particle size of 55 nm. Based on the differences between nano-Cu2O and bulk Cu2O, in-situ microcalorimetry was used to acquire fine thermodynamic information of Cu2O systems in HNO3. The reaction kinetic parameters of Cu2O were calculated by a combination of thermodynamic principles and kinetic transition state theory, whose results are discussed and verified with the kinetic models of a cube that has been built. The results demonstrate that unlike the higher reaction rate constant than bulk Cu2O, nano-Cu2O shows lower kinetic parameters, including apparent activation energy, pre-exponential factor, activation enthalpy, activation entropy and activation Gibbs free energy. Both the reaction rate constant and activation Gibbs free energy increase with increasing temperature. The kinetic models show that the main factors affecting the reaction kinetic parameters are as follows:(i) the partial molar surface enthalpy affects the apparent activation energy; (ii) the partial molar surface entropy affects the preexponential factor; and (iii) the partial molar surface Gibbs free energy affects the reaction rate constant. We also provide a universal theoretical model and experimental method for gaining and analyzing kinetic parameters of nanomaterial heterogeneous reactions.

Key words: In-situ microcalorimetry, Reaction kinetics, Kinetic model, Nanomaterial, Cubic cuprous oxide

MSC2000: 

  • O643