疏水二氧化硅球调控铁基催化剂在常压二氧化碳费托合成反应中的性能研究  

Study on performance of iron-based catalysts regulated by hydrophobic silica spheres in Fischer-Tropsch synthesis of carbon dioxide at atmospheric pressure

作　　者：陈加扬 陈杰 李玉峰 刘冰 胥月兵 刘小浩 CHEN Jiayang;CHEN Jie;LI Yufeng;LIU Bing;XU Yuebing;LIU Xiaohao(School of Chemical and Material Engineering,Jiangnan University,Wuxi 214122,Jiangsu,China)

机构地区：[1]江南大学化学与材料工程学院,江苏无锡214122

出　　处：《低碳化学与化工》2023年第3期32-40,共9页Low-Carbon Chemistry and Chemical Engineering

基　　金：国家自然科学基金(21878127);江南大学-中国石化催化剂有限公司协同创新合作项目(36100000-22-ZC0607-0035,36100000-22-ZC0607-0037)。

摘　　要：二氧化碳(CO_(2))铁基费托合成反应过程中生成的大量产物水是影响催化剂反应性能的重要因素。通过硅烷化对二氧化硅(SiO_(2))球表面进行疏水修饰,将其与铁基催化剂FeZnNa混合后应用于常压CO_(2)费托合成反应,考察了疏水SiO_(2)球与FeZnNa催化剂混合方式对反应性能的影响,并采用XRD、穆斯堡尔谱、光学接触角测定、N_(2)吸/脱附和程序升温脱附等表征方法分析了催化剂反应前后的物理化学性质。结果表明,疏水SiO_(2)球反应后仍保持良好的疏水性,相较于与没有疏水性的石英砂混合的FeZnNa催化剂,与疏水SiO_(2)球等体积颗粒混合的FeZnNa催化剂显示出更好的催化稳定性,在反应时间5~20 h内,CO_(2)转化率从24.9%下降到23.7%,而与疏水SiO_(2)球等质量颗粒混合和等质量粉末混合后的FeZnNa催化剂稳定性大幅下降,在相同反应时间内,CO_(2)转化率分别下降了9.4%和11.7%。相较于与疏水SiO_(2)球等体积颗粒混合,与疏水SiO_(2)球等质量颗粒混合的FeZnNa催化剂反应后Fe3C含量增加,而与疏水SiO_(2)球等质量粉末混合的FeZnNa催化剂反应后出现了大量的零价Fe,表明混合方式对反应过程中催化剂的铁物相演变有显著影响,从而导致催化活性和稳定性的明显差异。The large amount of water produced during the iron-based CO_(2) Fisher-Tropsch synthesis reaction plays a crucial role affecting the catalytic performance.The surface of hydrophobic SiO_(2) spheres was hydrophobic modified by silylation,which was mixed with FeZnNa catalysts to show its effect on the CO_(2) Fischer-Tropsch reaction at atmospheric pressure.The effects of mixing modes of SiO_(2) spheres and FeZnNa catalysts on the reaction performance of CO_(2) Fisher-Tropsch synthesis were investigated.A series of characterization,such as XRD,Mӧssbauer spectroscopy,contact angle measurements,N_(2) adsorption/desorption and temperature programmed desorption were performed to analyze the physicochemical properties of fresh and spent catalysts.The results show that the hydrophobic SiO_(2) spheres still maintain good hydrophobicity after reaction.Compared with the FeZnNa catalysts mixed with quartz sand without hydrophobicity,the FeZnNa catalysts mixed with hydrophobic SiO_(2) spheres with equal volume particles show better catalytic stability.During 5~20 h of reaction,the CO_(2) conversion decreases from 24.9%to 23.7%,while the stability of the FeZnNa catalysts mixed with hydrophobic SiO_(2) spheres with equal mass particles and equal mass powder decreases significantly.In the same time,the CO_(2) conversion rate decreases by 9.4%and 11.7%respectively.Compared with the mixing of equal volume particles,the content of Fe3C in the FeZnNa catalysts mixed with equal mass particles increases after the reaction,while a large amount of zero-valent iron appears after reaction of the FeZnNa catalyst mixed with equal mass powder,indicating that mixing modes have a significant impact on the phase evolution of iron in the catalyst during reaction,resulting in significant differences in catalytic activity and stability.

关 键 词：二氧化碳费托合成反应 疏水SiO_(2)球 铁基催化剂 混合方式 铁物相演变 催化性能 

分 类 号：TQ426[化学工程]