负载MgO-CeO_(2)改性活性炭的脱硫机理  

Desulfurization Mechanism of Modified Activated Carbon Loaded with MgO-CeO_(2)

作　　者：张锟 张艳娟 刘文虎[1] 张晓磊 ZHANG Kun;ZHANG Yanjuan;LIU Wenhu;ZHANG Xiaolei(Hunan Petrochemical Vocational Technology College,Yueyang Hunan 414000,China)

机构地区：[1]湖南石油化工职业技术学院,湖南岳阳414000

出　　处：《当代化工》2024年第10期2395-2400,共6页Contemporary Chemical Industry

基　　金：湖南省教育厅科学研究项目(项目编号:22C1068)。

摘　　要：通过XRD、H2-TPR、XPS等方法对MgO-CeO_(2)改性的煤基柱状成型商品活性炭的脱硫机理进行了研究。实验结果表明:高温煅烧改性,使MgO与CeO_(2)反应形成Ce-Mg-O固溶体,当MgO质量分数低于5%时,因固溶体的形成,XRD谱图上没有明显的MgO晶体衍射峰。MgO的加入改变了CeO_(2)的还原环境,加速了Ce^(4+)→Ce^(3+)的还原和氧空位的形成,其中4Ce6Mg/AC样品还原性最强。推测其脱硫机理为:SO_(2)因活性炭优良的吸附性能直接吸附;SO_(2)被CeO_(2)活性位点催化氧化,以硫酸盐的形式除去;SO_(2)被MgO活性位点化学吸附,以亚硫酸盐的形式除去;镁铈双金属氧化物之间存在协同效应,促进了晶格氧的迁移转化,显著增强了改性样品的脱硫性能。XRD,H2-TPR and XPS were used to study the desulfurization mechanism of MgO-CeO_(2)modified coal-based columnar commercial activated carbon.The experimental results showed that MgO and CeO_(2)reacted to form Ce-Mg-O solid solution by calcination modification at high temperature.When the mass fraction of MgO was less than 5%,there was no obvious MgO crystal diffraction peak on the XRD pattern due to the formation of solid solution.The addition of MgO changed the reduction environment of CeO_(2),accelerated the reduction of Ce^(4+)→Ce^(3+)and the formation of oxygen vacancy,among which 4Ce6Mg/AC sample had the strongest reduction.It is speculated that the desulfurization mechanism is as follows:SO_(2)directly adsorbs due to the excellent adsorption properties of activated carbon;SO_(2)is catalyzed by CeO_(2)active site and removed in the form of sulfate;SO_(2)is chemically adsorbed by the active site of MgO and removed in the form of sulfite;there is a synergistic effect between magnesium and cerium bimetallic oxides,which promotes the migration and transformation of lattice oxygen and significantly enhances the desulfurization performance of modified samples.

关 键 词：MGO CeO_(2) 活性炭 改性 吸附 催化 氧化 脱硫机理 

分 类 号：TQ424.1[化学工程] X511[环境科学与工程—环境工程]