h-BN掺杂Na2WO4-Mn/SiO2催化剂用于乙烷氧化脱氢制乙烯  

h-BN-Doped NaWO-Mn/SiO Catalysts for Oxidative Dehydrogenation of Ethane to Ethylene

作　　者：张琦 童金辉 丑凌军[2] 宋焕玲[2] 赵军[2] 赵华华[2] 闫亮[2] 杨建[2] ZHANG Qi;TONG Jin-hui;CHOU Ling-jun;SONG Huan-ling;ZHAO Jun;ZHAO Hua-hua;YAN Liang;YANG Jian(Key Laboratory of Polymer Materials of Gansu Province,Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education,College of Chemistry and Chemical Engineering,Northwest Normal University,Lanzhou 730070,China;State Key Laboratory for Oxo Synthesis and Selective Oxidation,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]西北师范大学化学化工学院,甘肃省高分子材料重点实验室生态环境相关高分子材料教育部重点实验室,甘肃兰州730070 [2]中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室,甘肃兰州730000

出　　处：《分子催化》2020年第6期495-504,I0001,共11页Journal of Molecular Catalysis(China)

摘　　要：采用混浆法制备了一系列六方氮化硼掺杂的Na2WO4/Mn/BxSiy催化剂,并应用于乙烷氧化脱氢制乙烯(ODHE).考察了Na2WO4/Mn/BxSiy催化剂的ODHE反应性能,并详细探讨了反应温度、稀释气比例等条件对催化剂反应活性的影响.结果表明,h-BN的掺杂显著提高了Na2WO4/Mn/BxSiy催化剂C2H4选择性.Na2WO4/Mn/B5.0Si95催化剂在700℃时,表现出相对较高的活性并且CO2生成量极低(>70%乙烯选择性,46.5%的乙烯收率,1.80%的CO2选择性).通过X-射线粉末衍射(XRD)、扫描电镜(SEM)、H2程序升温还原(H2-TPR)、O2程序升温脱附(O2-TPD)和C2H6程序升温脱附(C2H6-TPD)等手段对催化剂进行了表征.研究发现,h-BN的加入对改变催化剂表面元素的化学状态,形成更多具有低温活性的物相,抑制深度氧化均起到重要作用.同时,h-BN的掺杂也调变了催化剂的导热能力,避免床层热点的形成,提高了C2H4的选择性.A series of h-BN doped Na2WO4/Mn/BxSiy catalysts are prepared by mixture slurry method and evaluated by ODHE(oxidative dehydrogenation of ethane to ethylene).The Na2WO4/Mn/BxSiy catalyst were synthesized and the effect of reaction temperature and dilution gas ratio on the catalytic performance of the Na2WO4/Mn/BxSiy catalysts was investigated.The results show that h-BN exerted remarkable influence on the catalytic C2H4 selectivity of Na2WO4/Mn/BxSiy.Na2WO4/Mn/B5.0Si95 catalyst showed relatively high activity and CO2 production is very low(>70%C2H4 selectivity,46.5%C2H4 yield,1.80%CO2 selectivity)at the condition of temperature 700℃.And the catalysts are characterized by XRD,SEM,H2-TPR,O2-TPD,C2H6-TPD.It is found that the addition of h-BN plays an important role in inhibiting the deep oxidation by changing the chemical state of the surface elements of the catalyst and forming more phases with low temperature activity.Meanwhile,the doping of the h-BN also modulates the thermal conductivity of the catalyst,avoids the formation of hot spots in catalyst bed,and improves the selectivity of the C2H4.

关 键 词：乙烷 氧化脱氢 Na2WO4-Mn/SiO2 六方氮化硼 乙烯 

分 类 号：O643.32[理学—物理化学]