Physico-Geometrical Mechanism and Overall Kinetics of Thermally Induced Oxidative Decomposition of Tin(II) Oxalate in Air: Formation Process of Microstructural Tin(IV) Oxide
Physico-Geometrical Mechanism and Overall Kinetics of Thermally Induced Oxidative Decomposition of Tin(II) Oxalate in Air: Formation Process of Microstructural Tin(IV) Oxide
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DOI：
10.1021/jp505937k
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发表时间：
2014-08-07
影响因子：
3.7
通讯作者：
Koga, Nobuyoshi
中科院分区：
文献类型：
--
作者：
Kitabayashi, Suguru;Koga, Nobuyoshi
本研究主要研究流动空气中草酸锡(II)热诱导氧化分解生成微观结构TiN(IV)氧化物的物理几何机理和整体动力学。对两种不同形态的草酸锡(II)样品进行了动力学研究，包括热重和形态观察。反应在不同的步骤表现出不同的行为(多步行为)；因此，使用基于累积动力学方程的动力学分析将整个反应分解为每个反应步骤。氧化分解的特征是由表面反应引发的相界控制反应。在反应的早期阶段形成的表面产物层抑制了产物和反应气体的扩散。气体扩散通道是通过反应本身对表面产物层进行重构而产生的，残留反应以自催化反应的方式进行。动力学行为由特定的、瞬时形成的反应颗粒的结构特征下的自生成反应条件来调节，这些结构特征随所应用的反应条件而变化。因此，氧化分解的过程控制是控制生成的氧化锡(IV)的微观结构和物化性能的重要因素。
This study focuses on the physico-geometrical mechanism and the overall kinetics of the microstructural tin(IV) oxide formation process by the thermally induced oxidative decomposition of tin(II) oxalate in flowing air. Two tin(II) oxalate samples with different morphologies were subjected to a kinetic study involving thermogravimetrical and morphological observations. The reactions exhibited different behaviors at different steps (multistep behaviors); therefore, the overall reactions were resolved into each reaction step using kinetic analyses based on the cumulative kinetic equation. Oxidative decomposition is characterized by a phase boundary controlled reaction initiated by the surface reaction. The formation of the surface product layer at an early stage of the reaction inhibits diffusion of the product and reactant gases. Gaseous diffusion channels are produced via reformulation of the surface product layer by the reaction itself, and the residual reaction advances in the manner of autocatalytic reaction. The kinetic behavior is regulated by the self-generated reaction conditions under specific, transiently formed structural characteristics of the reacting particles, which vary depending on the applied reaction conditions. Therefore, the process control of the oxidative decomposition is an important factor for controlling the microstructure and physicochemical properties of the resulting tin(IV) oxide.