Promotion of graphitic carbon oxidation via stimulating CO2 desorption by calcium carbonate
Promotion of graphitic carbon oxidation via stimulating CO2 desorption by calcium carbonate
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通过碳酸钙刺激二氧化碳解吸促进石墨碳氧化
DOI：
10.1016/j.jhazmat.2018.09.048
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发表时间：
2019
影响因子：
13.6
通讯作者：
Nozaki Tomohiro
中科院分区：
文献类型：
--
作者：
Yao Shuiliang;Zhang Huanhuan;Chen Zhizong;Lin Hanghao;Han Shoushan;Wu Xinyue;Dong Ruoyu;Wu Zuliang;Nozaki Tomohiro
碳氧化有两个阶段，第一阶段是表面氧化物的形成，第二阶段是表面氧化物气化成CO2。碳酸钙（CaCO 3）被用来催化气化的表面氧化物。采用热重分析和原位漫反射红外光谱（DRIFTS）技术研究了催化剂对石墨氧化的催化作用及其催化机理。结果表明，CaCO 3氧化石墨的特征温度（T50）为946 K，比纯石墨氧化的T50低113 K。DRIFTS分析结果表明，温度高于473 K时，石墨表面生成了表面氧化物（吸附CO2和碳酸盐CO 32-），当CaCO 3存在时，石墨表面的碳酸盐产物消失;证实了CaCO 3表面生成了CO 32-，这种CO 32-可能更容易气化成气态CO2。动力学分析结果表明，CaCO 3促进石墨氧化的活化能为74.3 kJ mol−1，远低于石墨的活化能（148 kJ mol−1）。
Carbon oxidation has two stages, the first is the formation of surface oxides and the second is the gasification of the surface oxides to CO2. Calcium carbonate (CaCO3) was used to catalyze the gasification of the surface oxides. The catalytic effect of on graphite oxidation and its catalytic mechanism were studied by using thermogravimetric technique andin situdiffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). It was found that characteristic temperature (T50) of graphite oxidation with CaCO3was 946 K, 113 K lower than that of graphite only. DRIFTS analysis results show that surface oxides (adsorbed CO2and carbonate CO32−) were formed on the graphite surface at a temperature above 473 K, carbonate products on graphite surface disappeared when CaCO3was present; formation of CO32−on CaCO3surface was confirmed, this CO32−may be more easily gasified into gaseous CO2. The kinetic analysis results showed that CaCO3promoted graphite oxidation has an activation energy of 74.3 kJ mol−1, far lower than that of graphite (148 kJ mol−1).