热分解
粒径
化学
成核
动能
活化能
动力学
粒子(生态学)
热力学
氢
反应性(心理学)
分解
化学分解过程
反应速率
碳酸钾
分析化学(期刊)
物理化学
色谱法
有机化学
催化作用
病理
地质学
替代医学
物理
海洋学
医学
量子力学
作者
Mito Hotta,Taiga Tone,Nobuyoshi Koga
标识
DOI:10.1021/acs.jpcc.1c07231
摘要
In this study, we investigated the mechanisms of variations in the overall kinetic behavior of the physico-geometrical consecutive process of the surface reaction (SR) and phase boundary-controlled reaction (PBR) in solid–gas systems with varying particle size of the reactants. Thermal decomposition of potassium hydrogen carbonate (KHCO3) was selected as a suitable model reaction owing to the significant changes in its kinetic behavior with particle size and less sensitivity to experimental conditions for recording kinetic data. The reaction was characterized by an induction period (IP) accompanied by the formation of a gelatinated surface layer. The subsequent mass-loss process was indicated by the consecutive SR and PBR, which was accompanied by the nucleation and growth of solid products in the gelatinated layer and inward advancement of the reaction interface, respectively. Formal kinetic analyses of systematically recorded kinetic data revealed variations in the overall kinetic behaviors with the sample particle size, including changes in the variation trend of isoconversional activation energy values as the reaction progressed and the shape of the experimental master plot. The kinetics of each reaction step in the physico-geometrical consecutive process was investigated using an advanced kinetic approach based on an IP–SR–PBR model. The results revealed variations in the overall kinetic behaviors of the thermal decomposition of KHCO3 with particle size, owing to changes in the reactivity of the reactant surface in IP, overlapping degree of SR and PBR, and total migration length of the reaction interface in PBR.
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