MgX_(2)O_(4)(X=Cr、Fe、Mn)型尖晶石B位点阳离子对乙烷化学链氧化脱氢生成乙烯的影响  

Impact of B-site cations of MgX_(2)O_(4)(X=Cr,Fe,Mn)spinels on the chemical looping oxidative dehydrogenation of ethane to ethylene

作　　者：梁晓岑 王雪梅 幸子凡 毛敏 宋达 李杨 龙涛 周宇超 陈佩丽[3] 何方 LIANG Xiaocen;WANG Xuemei;XING Zifan;MAO Min;SONG Da;LI Yang;LONG Tao;ZHOU Yuchao;CHEN Peili;HE Fang(College of Chemistry and Bioengineering,Guilin University of Technology,Guilin 541006,China;Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials,College of Chemistry and Bioengineering,Guilin University of Technology,Guilin 541006,China;Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China;School of Energy Science and Engineering,University of Science and Technology of China,Hefei 230000,China)

机构地区：[1]桂林理工大学化学与生物工程学院,广西桂林541006 [2]桂林理工大学化学与生物工程学院,广西电化学与磁化学功能材料重点实验室,广西桂林541006 [3]中国科学院广州能源研究所,广东广州510640 [4]中国科学技术大学能源科学与工程学院,安徽合肥230000

出　　处：《燃料化学学报（中英文）》2024年第7期1006-1019,共14页Journal of Fuel Chemistry and Technology

摘　　要：化学链循环氧化脱氢技术(CL-ODH)是一个多功能的平台,它可以利用载氧体中晶格氧的选择性氧化这一特性,实现乙烷向乙烯的高值化转化。本研究探讨了MgX_(2)O_(4)(X=Cr、Fe或Mn)型尖晶石载氧体中B位元素对乙烷CL-ODH性能的影响。采用固定床和H_(2)-TPR、O_(2)-TPD、TG、原位拉曼、SEM、TEM等方法对MgX_(2)O_(4)尖晶石进行了性能测试和表征。结果表明,MgCr_(2)O_(4)仅释放微量表面吸附氧,更倾向于催化乙烷转化为焦炭和氢气。MgFe_(2)O_(4)通过提供更多的表面晶格氧,促进乙烷深度氧化成CO_(2)。MgMn_(2)O_(4)载氧体在乙烷CL-ODH反应中能够释放出大量的体相晶格氧,它可以选择性燃烧氢气以推进反应正向进行,增加乙烯的选择性,实现了73.72%的乙烷转化率和81.46%的乙烯选择性。此外,MgMn_(2)O_(4)催化剂在乙烷CL-ODH反应中进行了30次的氧化还原循环实验,表现出稳定的反应性能,在整个循环测试中乙烯收率大约为62.00%。MgX_(2)O_(4)尖晶石氧化物中B位元素影响了其晶格氧的供应能力,从而影响了其在乙烷CL-ODH反应中的性能。Chemical looping oxidative dehydrogenation(CL-ODH)provides a multifunctional conversion platform that can take advantage of the selective oxidation of lattice oxygen in oxygen carrier to achieve high-valued ethane to ethylene conversion.In this study,we explored the effect of B-site element in MgX_(2)O_(4)(X=Cr,Fe,or Mn)spinel-type oxygen carriers on the performance of ethane CL-ODH.The properties test and characterization of MgX_(2)O_(4) spinel were tested by fixed bed and H_(2)-TPR,O_(2)-TPD,TG,in-situ Raman,SEM,and TEM.The results showed that because MgCr_(2)O_(4) only released a small amount of adsorbed surface oxygen,it tended to catalyze the conversion of ethane to coke and hydrogen.MgFe_(2)O_(4) facilitated the deep oxidation of ethane into CO_(2) by providing more surface lattice oxygen.Meanwhile,since a significant amount of bulk lattice oxygen was released by the MgMn_(2)O_(4) oxygen carrier,it could burn hydrogen in a targeted manner to advance the reaction and increased ethylene's selectivity.Thereby,MgMn_(2)O_(4) achieved an ethane conversion of 73.72% with an ethylene selectivity of 81.46%.Furthermore,the MgMn_(2)O_(4) catalyst demonstrated stable reactivity and an ethylene yield of about 62.00%in ethane CL-ODH over the 30 redox cycles.The screening tests indicated that the B-site elements in MgX_(2)O_(4) spinel oxides could significantly influence their ability to supply lattice oxygen,thereby affecting their performance in ethane CLODH reaction.

关 键 词：乙烷CL-ODH MgX_(2)O_(4)尖晶石型载氧体 乙烷生产乙烯 MgMn_(2)O_(4) 

分 类 号：O643.36[理学—物理化学]