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采用程序升温在线质谱分析方法 ,研究了常压条件下CH4在Ni/Al2 O3催化剂上分解所形成的碳物种 ,发现CH4分解形成的NixC会首先转化成不与CO2 反应 ,但在 70 0℃左右可与O2 反应的碳 ;这种碳再向需在 80 0℃才能与O2 反应的石墨碳转化 .在较低的温度下 ,NixC向石墨碳转化的速度较慢 ,而在高温条件下转化速度大大加快 .在 70 0℃下 ,Ni/Al2 O3催化剂上的CH4部分氧化制合成气反应生成的积碳主要为石墨碳 ,是由CH4分解形成的NixC转化而成的 .在催化剂中添加适当的助剂 ,可提高NixC与氧的反应活性 ,抑制其向石墨碳转化 ,是改善催化剂抗积碳性能的有效途径 .
The method of temperature programmed in-line mass spectrometry was used to study the carbon species formed by the decomposition of CH4 on Ni / Al2 O3 catalyst under atmospheric pressure. It was found that NixC formed by the decomposition of CH4 was first converted to CO2 without reaction with CO2, Carbon that reacts with O2 This carbon is then converted to graphitic carbon which is to react with O2 at 80 ° C. At lower temperatures, NixC converts slowly to graphitic carbon, while at high temperatures the rate of conversion Greatly accelerated at 70 0 ° C, Ni / Al2 O3 catalyst on the partial oxidation of CH4 syngas generated by the reaction of carbon deposition is mainly carbon graphite, formed by the decomposition of CH4 NixC converted from the catalyst to add the appropriate Additives can improve the reactivity of NixC with oxygen and inhibit its conversion to graphitic carbon, which is an effective way to improve the anti-carbon deposition performance of the catalyst.