本文主要研究内容
作者田井清,李浩成,曾馨,王子春,黄骏,赵晨(2019)在《限域Ni/MCM-41催化抗积碳和金属烧结的甲烷干重整反应(英文)》一文中研究指出:干重整反应为同时转化两种主要的温室气体甲烷和二氧化碳为合成气(CO和H2).发展干重整高温反应是转化工业废气(如焦炉煤气、煤制油尾气等)为合成气平台分子的有效手段.由于廉价的金属镍具有良好的甲烷解离能力,因此干重整反应中二氧化碳的解离很关键,可添加如MgO, BaO, CaO等碱土氧化物来加强二氧化碳的吸附,或添加具有氧空位的CeO2, ZrO2, La2O3的氧化物来捕集二氧化碳.双金属Ni Fe催化剂中, Fe通过将CO2还原为CO和FeO来激活CO2,然后FeO可通过氧化还原反应将解离的C*转化为CO和Fe,从而实现高温下活化CO2和表面C去除的完美结合.干重整反应面临高温下催化剂金属中心烧结和催化剂表面积碳严重的问题,而将活性金属粒子限域是一种有效阻止金属高温烧结的方法.本文利用乙醇诱导的毛细管作用力,发展了均匀负载Ni纳米粒子于MCM-41直型孔道结构内的简易方法.该限域结构催化剂的Ni金属负载量为10 wt%, X射线粉末衍射(XRD)测试显示无明显的Ni衍射峰,表明Ni颗粒高度分散,透射电子显微镜(TEM)表征结果表明Ni颗粒大小为2 nm左右, Ni颗粒主要分布在MCM-41的孔道内.程序升温还原(TPR)表明该限域结构催化剂具有较高的还原温度,说明NiO与硅氧化物之间有较强的相互作用.在反应条件下(700℃,常压,空速为45000 mL/g/h),催化剂具有高的甲烷转化率(72%,接近该温度下的平衡转化率), TOF达到667 mol CH4/molsurf.Ni/h.经过200 h反应后,甲烷转化率未见明显下降, H2/CO摩尔比维持在0.87左右.反应后TEM结果显示, Ni颗粒未见明显团聚(其平均粒径为3-4 nm左右),没有观察到Ni颗粒被碳包覆的现象.同时,反应后催化剂的拉曼光谱测试结果表明,催化剂上积碳为无定型碳,程序升温氧化(TPO)测试说明这种无定型碳更容易被气化,不会导致催化剂失活,热重分析(TGA)表明其平均积碳速率为0.26 mg/g/h.对比Ni纳米粒子负载于MCM-41外表面的催化剂,其甲烷初始转化率为65%,并且在反应开始后的12 h内快速失活.反应60 h后催化剂的XRD测试结果表明, Ni的衍射峰变强, Ni晶粒尺寸增大,并且出现了明显的石墨化碳的衍射峰.进一步TEM结果显示,平均Ni颗粒尺寸增大到16.7 nm,且催化剂表面布满积碳生成的碳纳米管,从高分辨TEM结果可以看出,大颗粒的Ni表面被多层石墨化碳覆盖.TPO测试结果显示,这种碳更难被气化, TGA分析得出平均积碳速率达到3.2 mg/g/h,是限域结构催化剂的12倍.这种石墨化碳阻断了金属中心和反应物分子间的接触,导致催化剂失活.
Abstract
gan chong zheng fan ying wei tong shi zhuai hua liang chong zhu yao de wen shi qi ti jia wan he er yang hua tan wei ge cheng qi (COhe H2).fa zhan gan chong zheng gao wen fan ying shi zhuai hua gong ye fei qi (ru jiao lu mei qi 、mei zhi you wei qi deng )wei ge cheng qi ping tai fen zi de you xiao shou duan .you yu lian jia de jin shu nie ju you liang hao de jia wan jie li neng li ,yin ci gan chong zheng fan ying zhong er yang hua tan de jie li hen guan jian ,ke tian jia ru MgO, BaO, CaOdeng jian tu yang hua wu lai jia jiang er yang hua tan de xi fu ,huo tian jia ju you yang kong wei de CeO2, ZrO2, La2O3de yang hua wu lai bu ji er yang hua tan .shuang jin shu Ni Fecui hua ji zhong , Fetong guo jiang CO2hai yuan wei COhe FeOlai ji huo CO2,ran hou FeOke tong guo yang hua hai yuan fan ying jiang jie li de C*zhuai hua wei COhe Fe,cong er shi xian gao wen xia huo hua CO2he biao mian Cqu chu de wan mei jie ge .gan chong zheng fan ying mian lin gao wen xia cui hua ji jin shu zhong xin shao jie he cui hua ji biao mian ji tan yan chong de wen ti ,er jiang huo xing jin shu li zi xian yu shi yi chong you xiao zu zhi jin shu gao wen shao jie de fang fa .ben wen li yong yi chun you dao de mao xi guan zuo yong li ,fa zhan le jun yun fu zai Nina mi li zi yu MCM-41zhi xing kong dao jie gou nei de jian yi fang fa .gai xian yu jie gou cui hua ji de Nijin shu fu zai liang wei 10 wt%, Xshe xian fen mo yan she (XRD)ce shi xian shi mo ming xian de Niyan she feng ,biao ming Nike li gao du fen san ,tou she dian zi xian wei jing (TEM)biao zheng jie guo biao ming Nike li da xiao wei 2 nmzuo you , Nike li zhu yao fen bu zai MCM-41de kong dao nei .cheng xu sheng wen hai yuan (TPR)biao ming gai xian yu jie gou cui hua ji ju you jiao gao de hai yuan wen du ,shui ming NiOyu gui yang hua wu zhi jian you jiao jiang de xiang hu zuo yong .zai fan ying tiao jian xia (700℃,chang ya ,kong su wei 45000 mL/g/h),cui hua ji ju you gao de jia wan zhuai hua lv (72%,jie jin gai wen du xia de ping heng zhuai hua lv ), TOFda dao 667 mol CH4/molsurf.Ni/h.jing guo 200 hfan ying hou ,jia wan zhuai hua lv wei jian ming xian xia jiang , H2/COma er bi wei chi zai 0.87zuo you .fan ying hou TEMjie guo xian shi , Nike li wei jian ming xian tuan ju (ji ping jun li jing wei 3-4 nmzuo you ),mei you guan cha dao Nike li bei tan bao fu de xian xiang .tong shi ,fan ying hou cui hua ji de la man guang pu ce shi jie guo biao ming ,cui hua ji shang ji tan wei mo ding xing tan ,cheng xu sheng wen yang hua (TPO)ce shi shui ming zhe chong mo ding xing tan geng rong yi bei qi hua ,bu hui dao zhi cui hua ji shi huo ,re chong fen xi (TGA)biao ming ji ping jun ji tan su lv wei 0.26 mg/g/h.dui bi Nina mi li zi fu zai yu MCM-41wai biao mian de cui hua ji ,ji jia wan chu shi zhuai hua lv wei 65%,bing ju zai fan ying kai shi hou de 12 hnei kuai su shi huo .fan ying 60 hhou cui hua ji de XRDce shi jie guo biao ming , Nide yan she feng bian jiang , Nijing li che cun zeng da ,bing ju chu xian le ming xian de dan mo hua tan de yan she feng .jin yi bu TEMjie guo xian shi ,ping jun Nike li che cun zeng da dao 16.7 nm,ju cui hua ji biao mian bu man ji tan sheng cheng de tan na mi guan ,cong gao fen bian TEMjie guo ke yi kan chu ,da ke li de Nibiao mian bei duo ceng dan mo hua tan fu gai .TPOce shi jie guo xian shi ,zhe chong tan geng nan bei qi hua , TGAfen xi de chu ping jun ji tan su lv da dao 3.2 mg/g/h,shi xian yu jie gou cui hua ji de 12bei .zhe chong dan mo hua tan zu duan le jin shu zhong xin he fan ying wu fen zi jian de jie chu ,dao zhi cui hua ji shi huo .
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论文作者分别是来自Chinese Journal of Catalysis的田井清,李浩成,曾馨,王子春,黄骏,赵晨,发表于刊物Chinese Journal of Catalysis2019年09期论文,是一篇关于甲烷干气重整论文,限域结构论文,利用论文,抗积碳论文,高温稳定催化剂论文,Chinese Journal of Catalysis2019年09期论文的文章。本文可供学术参考使用,各位学者可以免费参考阅读下载,文章观点不代表本站观点,资料来自Chinese Journal of Catalysis2019年09期论文网站,若本站收录的文献无意侵犯了您的著作版权,请联系我们删除。
标签:甲烷干气重整论文; 限域结构论文; 利用论文; 抗积碳论文; 高温稳定催化剂论文; Chinese Journal of Catalysis2019年09期论文;